<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:20e6b28d-757f-44ae-b009-98776177e1f5,g:4d59985b-132c-4db0-8a17-1c1cd4970377-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.itron.com/role/ConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="itri-20240930.xsd#ConsolidatedStatementsofOperations"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_ddbc7c5f-6365-4d63-97f3-d310aa2071bf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_StatementTable_ddbc7c5f-6365-4d63-97f3-d310aa2071bf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_67a8ea61-176c-4fe5-b5ee-0637d290172d" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_ddbc7c5f-6365-4d63-97f3-d310aa2071bf" xlink:to="loc_srt_ProductOrServiceAxis_67a8ea61-176c-4fe5-b5ee-0637d290172d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_67a8ea61-176c-4fe5-b5ee-0637d290172d_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_67a8ea61-176c-4fe5-b5ee-0637d290172d" xlink:to="loc_srt_ProductsAndServicesDomain_67a8ea61-176c-4fe5-b5ee-0637d290172d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_4e33e7e2-ba77-469d-849e-d58aef592307" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_67a8ea61-176c-4fe5-b5ee-0637d290172d" xlink:to="loc_srt_ProductsAndServicesDomain_4e33e7e2-ba77-469d-849e-d58aef592307" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_91317407-89ae-4d6b-b01d-4f280e15dbe8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4e33e7e2-ba77-469d-849e-d58aef592307" xlink:to="loc_us-gaap_ProductMember_91317407-89ae-4d6b-b01d-4f280e15dbe8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_40aa2ec8-fc69-494e-9c57-3c4c017630b8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4e33e7e2-ba77-469d-849e-d58aef592307" xlink:to="loc_us-gaap_ServiceMember_40aa2ec8-fc69-494e-9c57-3c4c017630b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_bf053d36-2c3d-4f04-819f-d98164258fa8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_RevenuesAbstract_bf053d36-2c3d-4f04-819f-d98164258fa8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6811e214-40a1-49d9-8603-648dc90c4263" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_bf053d36-2c3d-4f04-819f-d98164258fa8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_6811e214-40a1-49d9-8603-648dc90c4263" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_8a6f7945-3cac-4675-9d4b-b8770064b120" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_CostOfRevenueAbstract_8a6f7945-3cac-4675-9d4b-b8770064b120" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_724ef4f7-99d5-4ceb-b226-27bd9e41c25f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_8a6f7945-3cac-4675-9d4b-b8770064b120" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_724ef4f7-99d5-4ceb-b226-27bd9e41c25f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_2a4156fb-0edc-42b4-8b6f-18df81bf5648" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_GrossProfit_2a4156fb-0edc-42b4-8b6f-18df81bf5648" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_90b11151-31e0-43a2-9048-213bce87abd2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_90b11151-31e0-43a2-9048-213bce87abd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_b794146a-b0c8-4047-8c2d-dedf5a0e3198" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_b794146a-b0c8-4047-8c2d-dedf5a0e3198" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_49f53575-c5aa-4518-b19c-9224cace3e04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_49f53575-c5aa-4518-b19c-9224cace3e04" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_GainLossOnRestructuring_30b0c619-e951-43c9-9161-5940ebf4f3d6" xlink:href="itri-20240930.xsd#itri_GainLossOnRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_itri_GainLossOnRestructuring_30b0c619-e951-43c9-9161-5940ebf4f3d6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfOtherAssets_57f672aa-5bf2-4e8e-818f-21d308f02960" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnSaleOfOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_GainLossOnSaleOfOtherAssets_57f672aa-5bf2-4e8e-818f-21d308f02960" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_f2b9979a-40d2-4d8b-aad9-d2d113885cba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_OperatingExpenses_f2b9979a-40d2-4d8b-aad9-d2d113885cba" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_697b894a-e1e5-4300-aa70-a4d7c09ec98d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_7f6556a3-c5f0-4f22-a1ab-e04c0d568b26" xlink:to="loc_us-gaap_OperatingIncomeLoss_697b894a-e1e5-4300-aa70-a4d7c09ec98d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOther_6f4dd138-bc0e-4f12-9363-72548362310f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestIncomeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:to="loc_us-gaap_InterestIncomeOther_6f4dd138-bc0e-4f12-9363-72548362310f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_54a3a12d-c754-4dc9-a0a8-2e6fcba4bb68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:to="loc_us-gaap_InterestExpense_54a3a12d-c754-4dc9-a0a8-2e6fcba4bb68" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_742135fb-a10e-499c-bfe2-aac0674044df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_742135fb-a10e-499c-bfe2-aac0674044df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_9c39db63-426d-4738-b65b-e03d72be8791" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cacfb1c3-4e6c-4cca-b0b5-8ac3985cfb4b" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_9c39db63-426d-4738-b65b-e03d72be8791" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_32ded155-02b4-47c3-9d3e-b3097241ffb6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_32ded155-02b4-47c3-9d3e-b3097241ffb6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_b6a7ad2d-db71-4453-81c7-1a0fecbf32ab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_b6a7ad2d-db71-4453-81c7-1a0fecbf32ab" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_14eff181-807b-424b-8fc2-45538c11ef30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_ProfitLoss_14eff181-807b-424b-8fc2-45538c11ef30" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_2aef61a8-08f2-4c41-b886-3485654345d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_2aef61a8-08f2-4c41-b886-3485654345d0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_a1ca7152-f729-47cc-a80d-298ae2b90657" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_NetIncomeLoss_a1ca7152-f729-47cc-a80d-298ae2b90657" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_afc983c2-ac1b-4a7b-bcc2-68cc0e6f3a44" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_EarningsPerShareBasic_afc983c2-ac1b-4a7b-bcc2-68cc0e6f3a44" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_baed216b-4c5f-4a48-9400-b7ee2391ea7a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_EarningsPerShareDiluted_baed216b-4c5f-4a48-9400-b7ee2391ea7a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_c0df4af1-bf1c-4bf7-a8b8-3eea5901738b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_c0df4af1-bf1c-4bf7-a8b8-3eea5901738b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_f720deb0-cab5-44c8-9864-bc1e0c94f87f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b54effa9-bda4-461a-af88-e8ccbcbb77f8" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_f720deb0-cab5-44c8-9864-bc1e0c94f87f" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/ConsolidatedStatementsofEquityStatement" xlink:type="simple" xlink:href="itri-20240930.xsd#ConsolidatedStatementsofEquityStatement"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ConsolidatedStatementsofEquityStatement" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_ee00f2ad-9691-4399-b959-42776a3e9f0b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_7f4742b2-edf1-487f-b7ac-1c474d8c8cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_ee00f2ad-9691-4399-b959-42776a3e9f0b" xlink:to="loc_us-gaap_StatementTable_7f4742b2-edf1-487f-b7ac-1c474d8c8cfa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_ceea1925-be6b-4933-bc60-c5b35182bed5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_7f4742b2-edf1-487f-b7ac-1c474d8c8cfa" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_ceea1925-be6b-4933-bc60-c5b35182bed5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ceea1925-be6b-4933-bc60-c5b35182bed5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ceea1925-be6b-4933-bc60-c5b35182bed5" xlink:to="loc_us-gaap_EquityComponentDomain_ceea1925-be6b-4933-bc60-c5b35182bed5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9b9a9611-ca41-4508-b563-4425f52222b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ceea1925-be6b-4933-bc60-c5b35182bed5" xlink:to="loc_us-gaap_EquityComponentDomain_9b9a9611-ca41-4508-b563-4425f52222b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9b9a9611-ca41-4508-b563-4425f52222b6" xlink:to="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_716d7a6b-73af-426d-ad03-6f0a70740b86" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:to="loc_us-gaap_CommonStockMember_716d7a6b-73af-426d-ad03-6f0a70740b86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_be4eeb9c-1ae7-491c-9f12-2af8e71b691f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:to="loc_us-gaap_CommonStockIncludingAdditionalPaidInCapitalMember_be4eeb9c-1ae7-491c-9f12-2af8e71b691f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_2956124a-d543-4c6c-92ab-e3daeac26b6b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_2956124a-d543-4c6c-92ab-e3daeac26b6b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_988e2387-3037-4fdb-9a2a-1f600efe1093" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_cd81377b-a74e-4688-9096-f2052900efd2" xlink:to="loc_us-gaap_RetainedEarningsMember_988e2387-3037-4fdb-9a2a-1f600efe1093" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_39ecf132-350b-428f-b158-ec4a2187973b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9b9a9611-ca41-4508-b563-4425f52222b6" xlink:to="loc_us-gaap_NoncontrollingInterestMember_39ecf132-350b-428f-b158-ec4a2187973b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_ee00f2ad-9691-4399-b959-42776a3e9f0b" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_67cdf2a0-0070-486a-ac8c-3a8e249abfd9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_67cdf2a0-0070-486a-ac8c-3a8e249abfd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_902fd47b-c836-4ece-b4f6-09adfe2030a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_902fd47b-c836-4ece-b4f6-09adfe2030a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_98fcf810-27b2-4074-b4ea-f71eeab230a6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_ProfitLoss_98fcf810-27b2-4074-b4ea-f71eeab230a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8ef01c8e-717e-49b5-b521-6f84fb2af04f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8ef01c8e-717e-49b5-b521-6f84fb2af04f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_34c21e99-ee59-49c4-bd22-0226a669da30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_34c21e99-ee59-49c4-bd22-0226a669da30" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_ae1500f5-cc8c-4164-a6ec-ea96e5973fca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_ae1500f5-cc8c-4164-a6ec-ea96e5973fca" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_fa2d5f83-cdab-4a66-8a5a-7dc001956426" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_fa2d5f83-cdab-4a66-8a5a-7dc001956426" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_f7139959-ab68-4d91-8196-298a2135de4d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_f7139959-ab68-4d91-8196-298a2135de4d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_ShareRepurchaseProgramExciseTax_792c1157-7cec-415d-8cd9-d1dc850f962b" xlink:href="itri-20240930.xsd#itri_ShareRepurchaseProgramExciseTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_itri_ShareRepurchaseProgramExciseTax_792c1157-7cec-415d-8cd9-d1dc850f962b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_PaymentsOnCallSpreadForConvertibleOfferingNetOfTax_5e8f9e09-7f93-4e6b-8e88-796d18899bc4" xlink:href="itri-20240930.xsd#itri_PaymentsOnCallSpreadForConvertibleOfferingNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_itri_PaymentsOnCallSpreadForConvertibleOfferingNetOfTax_5e8f9e09-7f93-4e6b-8e88-796d18899bc4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_4b732022-024e-43fc-86b8-452489abc369" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_4b732022-024e-43fc-86b8-452489abc369" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_c5e1767d-4052-4301-81e0-b01fc45140b5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_c5e1767d-4052-4301-81e0-b01fc45140b5" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_RegistrationFee_9c708a40-3e30-43a2-aee8-57b7fdc1230f" xlink:href="itri-20240930.xsd#itri_RegistrationFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_adaccc1b-5a78-4c61-a83a-f59eb5d8822a" xlink:to="loc_itri_RegistrationFee_9c708a40-3e30-43a2-aee8-57b7fdc1230f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_fbe9f5c7-904b-4a6c-9aae-b5fb94a938d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_71a7f0bb-092d-4710-aaee-7ba1e57fdff7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#SummaryofSignificantAccountingPoliciesDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/SummaryofSignificantAccountingPoliciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_144f8141-33cd-431c-88ed-d680d1ced83d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_5a775b06-ffca-4eb4-a1aa-dee8e287e275" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_144f8141-33cd-431c-88ed-d680d1ced83d" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_5a775b06-ffca-4eb4-a1aa-dee8e287e275" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgingPurposeAxis_ea248ebb-9729-4454-b01a-affb326de0a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgingPurposeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_5a775b06-ffca-4eb4-a1aa-dee8e287e275" xlink:to="loc_us-gaap_PledgingPurposeAxis_ea248ebb-9729-4454-b01a-affb326de0a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgingPurposeDomain_ea248ebb-9729-4454-b01a-affb326de0a9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgingPurposeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PledgingPurposeAxis_ea248ebb-9729-4454-b01a-affb326de0a9" xlink:to="loc_us-gaap_PledgingPurposeDomain_ea248ebb-9729-4454-b01a-affb326de0a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PledgingPurposeDomain_92c6e149-7b7f-4534-9dbf-4d22b07fa1d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PledgingPurposeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PledgingPurposeAxis_ea248ebb-9729-4454-b01a-affb326de0a9" xlink:to="loc_us-gaap_PledgingPurposeDomain_92c6e149-7b7f-4534-9dbf-4d22b07fa1d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_3aeef478-e74d-4655-bb1f-a088a9f141f3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PledgingPurposeDomain_92c6e149-7b7f-4534-9dbf-4d22b07fa1d7" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_3aeef478-e74d-4655-bb1f-a088a9f141f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_9a90537d-1892-413d-b91f-fc179b77cd76" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_144f8141-33cd-431c-88ed-d680d1ced83d" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_9a90537d-1892-413d-b91f-fc179b77cd76" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/EarningsPerShareConvertibleSeniorNotesandWarrantsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#EarningsPerShareConvertibleSeniorNotesandWarrantsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/EarningsPerShareConvertibleSeniorNotesandWarrantsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_70a6e3c0-1054-4783-88bd-32c74c60dde1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:to="loc_us-gaap_DebtInstrumentTable_70a6e3c0-1054-4783-88bd-32c74c60dde1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_9e10bcff-a8d6-450d-9fba-618aef989a68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_70a6e3c0-1054-4783-88bd-32c74c60dde1" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_9e10bcff-a8d6-450d-9fba-618aef989a68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e10bcff-a8d6-450d-9fba-618aef989a68_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_9e10bcff-a8d6-450d-9fba-618aef989a68" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_9e10bcff-a8d6-450d-9fba-618aef989a68_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_3e24b0a5-0453-4e0e-bcc7-d19b01258f98" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_9e10bcff-a8d6-450d-9fba-618aef989a68" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_3e24b0a5-0453-4e0e-bcc7-d19b01258f98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_62ad6b41-fa17-4db1-93f2-d20eb5379541" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_3e24b0a5-0453-4e0e-bcc7-d19b01258f98" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_62ad6b41-fa17-4db1-93f2-d20eb5379541" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CommonStockConversionPrice_fec90069-aa22-49f7-ba31-e85f7fbef391" xlink:href="itri-20240930.xsd#itri_CommonStockConversionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:to="loc_itri_CommonStockConversionPrice_fec90069-aa22-49f7-ba31-e85f7fbef391" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_bec7ee15-1891-47c4-945e-d7a9febdf7fb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_bec7ee15-1891-47c4-945e-d7a9febdf7fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_60875885-c363-4c38-bfa0-9b04bb097d9b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_60875885-c363-4c38-bfa0-9b04bb097d9b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_4cbbd803-aa7e-4480-a2a1-e6a14b1c2ebc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b67ae73c-7a4a-423f-8127-194997dafde5" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_4cbbd803-aa7e-4480-a2a1-e6a14b1c2ebc" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/EarningsPerShareConvertibleNoteHedgeTransactionsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#EarningsPerShareConvertibleNoteHedgeTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/EarningsPerShareConvertibleNoteHedgeTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_920c1900-ef73-4a9b-bda6-fdd6ca848388" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_ea6ab3fe-e664-4020-b170-664945f7a4b0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_920c1900-ef73-4a9b-bda6-fdd6ca848388" xlink:to="loc_us-gaap_DebtInstrumentTable_ea6ab3fe-e664-4020-b170-664945f7a4b0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0b4d8858-fc4a-4db9-a7a6-cac7f4997179" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_ea6ab3fe-e664-4020-b170-664945f7a4b0" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0b4d8858-fc4a-4db9-a7a6-cac7f4997179" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_0b4d8858-fc4a-4db9-a7a6-cac7f4997179_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0b4d8858-fc4a-4db9-a7a6-cac7f4997179" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_0b4d8858-fc4a-4db9-a7a6-cac7f4997179_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7bd58d34-ae24-4414-b5ac-5064b55ec948" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0b4d8858-fc4a-4db9-a7a6-cac7f4997179" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7bd58d34-ae24-4414-b5ac-5064b55ec948" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_a51cf0c1-65e0-4b56-b29c-c48340631553" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7bd58d34-ae24-4414-b5ac-5064b55ec948" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_a51cf0c1-65e0-4b56-b29c-c48340631553" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_cedf645c-791a-45db-a46e-b829a7896868" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_920c1900-ef73-4a9b-bda6-fdd6ca848388" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_cedf645c-791a-45db-a46e-b829a7896868" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CommonStockConversionPrice_b40c504a-78a9-45ac-8803-4b18cb989fda" xlink:href="itri-20240930.xsd#itri_CommonStockConversionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_920c1900-ef73-4a9b-bda6-fdd6ca848388" xlink:to="loc_itri_CommonStockConversionPrice_b40c504a-78a9-45ac-8803-4b18cb989fda" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/EarningsPerShare2024NotesandCappedCallTransactionDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#EarningsPerShare2024NotesandCappedCallTransactionDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/EarningsPerShare2024NotesandCappedCallTransactionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_647b9ed7-1d50-4b60-b164-bcbd8c7f1ac9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:to="loc_us-gaap_DebtInstrumentTable_647b9ed7-1d50-4b60-b164-bcbd8c7f1ac9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_3c828ca0-698d-4e72-8843-a8c8dcb7bb24" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_647b9ed7-1d50-4b60-b164-bcbd8c7f1ac9" xlink:to="loc_us-gaap_DebtInstrumentAxis_3c828ca0-698d-4e72-8843-a8c8dcb7bb24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3c828ca0-698d-4e72-8843-a8c8dcb7bb24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_3c828ca0-698d-4e72-8843-a8c8dcb7bb24" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3c828ca0-698d-4e72-8843-a8c8dcb7bb24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_025c0c5e-cd26-4b14-bca4-3ea48fac3765" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_3c828ca0-698d-4e72-8843-a8c8dcb7bb24" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_025c0c5e-cd26-4b14-bca4-3ea48fac3765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2021NotesMember_97369269-92b6-4f00-998b-e0fae0d4f937" xlink:href="itri-20240930.xsd#itri_A2021NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_025c0c5e-cd26-4b14-bca4-3ea48fac3765" xlink:to="loc_itri_A2021NotesMember_97369269-92b6-4f00-998b-e0fae0d4f937" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2024NotesMember_e0f970f7-271e-4ae7-8e01-ad0562a22385" xlink:href="itri-20240930.xsd#itri_A2024NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_025c0c5e-cd26-4b14-bca4-3ea48fac3765" xlink:to="loc_itri_A2024NotesMember_e0f970f7-271e-4ae7-8e01-ad0562a22385" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_a257ca25-fd62-424d-b1dc-1534417b468b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityEquityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_647b9ed7-1d50-4b60-b164-bcbd8c7f1ac9" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_a257ca25-fd62-424d-b1dc-1534417b468b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a257ca25-fd62-424d-b1dc-1534417b468b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_a257ca25-fd62-424d-b1dc-1534417b468b" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a257ca25-fd62-424d-b1dc-1534417b468b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4ce6ba78-9ff8-4e23-b718-84dfcd42b229" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_a257ca25-fd62-424d-b1dc-1534417b468b" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4ce6ba78-9ff8-4e23-b718-84dfcd42b229" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CallOptionMember_85fde6ca-4586-4ed5-bc60-351668412867" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CallOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4ce6ba78-9ff8-4e23-b718-84dfcd42b229" xlink:to="loc_us-gaap_CallOptionMember_85fde6ca-4586-4ed5-bc60-351668412867" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_6b3c841f-66fc-4fe1-9c64-be55ba90029d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_6b3c841f-66fc-4fe1-9c64-be55ba90029d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityShares_c198d745-6fca-4254-805f-6e647769b38a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityShares_c198d745-6fca-4254-805f-6e647769b38a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_8f5f7db2-78b2-40fc-a9e5-99e16aeff634" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityStrikePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_8f5f7db2-78b2-40fc-a9e5-99e16aeff634" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OptionIndexedToIssuersEquityCapPrice_82a3376a-5652-46ed-ac71-d7206d5876c4" xlink:href="itri-20240930.xsd#itri_OptionIndexedToIssuersEquityCapPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_f29bdc29-36c0-4b03-80cd-949fc8519d06" xlink:to="loc_itri_OptionIndexedToIssuersEquityCapPrice_82a3376a-5652-46ed-ac71-d7206d5876c4" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/IntangibleAssetsandLiabilitiesGrossCarryingAmountandAccumulatedAmortizationDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#IntangibleAssetsandLiabilitiesGrossCarryingAmountandAccumulatedAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/IntangibleAssetsandLiabilitiesGrossCarryingAmountandAccumulatedAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_bcbf54f2-9d10-4b5e-84e1-34e4c2045af2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_bcbf54f2-9d10-4b5e-84e1-34e4c2045af2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b258bb03-785e-4e79-aad9-951441325846" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_bcbf54f2-9d10-4b5e-84e1-34e4c2045af2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b258bb03-785e-4e79-aad9-951441325846" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b258bb03-785e-4e79-aad9-951441325846_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b258bb03-785e-4e79-aad9-951441325846" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b258bb03-785e-4e79-aad9-951441325846_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b258bb03-785e-4e79-aad9-951441325846" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_1ee847ca-f871-4570-be0a-f6e397722a11" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_1ee847ca-f871-4570-be0a-f6e397722a11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_173073e6-926c-4f64-82f3-06bc16ebbaf6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:to="loc_us-gaap_CustomerRelationshipsMember_173073e6-926c-4f64-82f3-06bc16ebbaf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_87b112e3-00b1-4820-a952-46504b0f2477" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_87b112e3-00b1-4820-a952-46504b0f2477" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_f06713fa-66a9-4415-8fb6-6ed4f9437120" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_63b0519b-33ac-493d-ab79-1dd5c88ee45d" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_f06713fa-66a9-4415-8fb6-6ed4f9437120" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_7bf582f4-45a6-417f-969c-a69e686f1d0b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_7bf582f4-45a6-417f-969c-a69e686f1d0b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_d733bb95-a1e3-46ff-926c-64dbf788d973" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_d733bb95-a1e3-46ff-926c-64dbf788d973" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_88392dc2-b7bc-4376-b261-c61e108a4577" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_88392dc2-b7bc-4376-b261-c61e108a4577" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_d43f8b8f-6b79-41ec-80ae-6f4bc8316755" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_d43f8b8f-6b79-41ec-80ae-6f4bc8316755" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_34bf0d6d-5a4a-4986-86f3-a32720694950" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_34bf0d6d-5a4a-4986-86f3-a32720694950" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FinitelivedintangibleliabilitiesGross_e5a67009-c2b0-443c-8380-9549e00aa33e" xlink:href="itri-20240930.xsd#itri_FinitelivedintangibleliabilitiesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_itri_FinitelivedintangibleliabilitiesGross_e5a67009-c2b0-443c-8380-9549e00aa33e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FiniteLivedIntangibleLiabilitiesAccumulatedAccretion_78e7b246-ea13-4f31-ac1b-5b135ce9cb56" xlink:href="itri-20240930.xsd#itri_FiniteLivedIntangibleLiabilitiesAccumulatedAccretion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_itri_FiniteLivedIntangibleLiabilitiesAccumulatedAccretion_78e7b246-ea13-4f31-ac1b-5b135ce9cb56" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FiniteLivedIntangibleLiabilitiesNet_18dd012e-9084-4681-8a67-cc2d731570d6" xlink:href="itri-20240930.xsd#itri_FiniteLivedIntangibleLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_118aef3e-1426-46bb-8d57-9fbe42ae2d04" xlink:to="loc_itri_FiniteLivedIntangibleLiabilitiesNet_18dd012e-9084-4681-8a67-cc2d731570d6" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/SummaryofIntangibleAssetAccountActivityDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#SummaryofIntangibleAssetAccountActivityDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/SummaryofIntangibleAssetAccountActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_9c38f52c-31a0-42d4-a096-674c85a5d9e9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_9c38f52c-31a0-42d4-a096-674c85a5d9e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_225ea60a-e7b7-4e69-b217-57e544fd3946" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_9c38f52c-31a0-42d4-a096-674c85a5d9e9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_225ea60a-e7b7-4e69-b217-57e544fd3946" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_225ea60a-e7b7-4e69-b217-57e544fd3946_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_225ea60a-e7b7-4e69-b217-57e544fd3946" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_225ea60a-e7b7-4e69-b217-57e544fd3946_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5707080f-77bb-4867-b960-8caf77023ca4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_225ea60a-e7b7-4e69-b217-57e544fd3946" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5707080f-77bb-4867-b960-8caf77023ca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_4063ad77-85fd-4bad-ae78-ddd93d8b73aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5707080f-77bb-4867-b960-8caf77023ca4" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_4063ad77-85fd-4bad-ae78-ddd93d8b73aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CustomerContractsAndRelationshipsMember_03601a18-7b30-48a4-9faf-734d12a9ddf0" xlink:href="itri-20240930.xsd#itri_CustomerContractsAndRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5707080f-77bb-4867-b960-8caf77023ca4" xlink:to="loc_itri_CustomerContractsAndRelationshipsMember_03601a18-7b30-48a4-9faf-734d12a9ddf0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_c6221599-1a15-4a0e-adfc-b05a176968c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_9c38f52c-31a0-42d4-a096-674c85a5d9e9" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_c6221599-1a15-4a0e-adfc-b05a176968c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c6221599-1a15-4a0e-adfc-b05a176968c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c6221599-1a15-4a0e-adfc-b05a176968c7" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c6221599-1a15-4a0e-adfc-b05a176968c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_033722e6-cb6d-4f0d-92e9-2c33888badcf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c6221599-1a15-4a0e-adfc-b05a176968c7" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_033722e6-cb6d-4f0d-92e9-2c33888badcf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_ElpisSquaredMember_266d1147-6dd1-4711-9063-3af000ae73df" xlink:href="itri-20240930.xsd#itri_ElpisSquaredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_033722e6-cb6d-4f0d-92e9-2c33888badcf" xlink:to="loc_itri_ElpisSquaredMember_266d1147-6dd1-4711-9063-3af000ae73df" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_cee2c9f4-d1bf-4d82-a7c2-66ee498543e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_cee2c9f4-d1bf-4d82-a7c2-66ee498543e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_9145d331-d11e-40fb-8837-d689f6493a40" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_9145d331-d11e-40fb-8837-d689f6493a40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_900588f3-81f1-4695-a46d-a95d9909571d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss_900588f3-81f1-4695-a46d-a95d9909571d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_3350d989-46b2-4973-96ee-cc8b25019c33" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FinitelivedintangibleliabilitiesGross_ca3b6ba7-8f66-45aa-80b0-19f64036096e" xlink:href="itri-20240930.xsd#itri_FinitelivedintangibleliabilitiesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_itri_FinitelivedintangibleliabilitiesGross_ca3b6ba7-8f66-45aa-80b0-19f64036096e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FiniteLivedIntangibleLiabilitiesForeignCurrencyTranslationGainLoss_e033defe-c78e-4b98-b0fb-51cb55e13bdb" xlink:href="itri-20240930.xsd#itri_FiniteLivedIntangibleLiabilitiesForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_itri_FiniteLivedIntangibleLiabilitiesForeignCurrencyTranslationGainLoss_e033defe-c78e-4b98-b0fb-51cb55e13bdb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_FinitelivedintangibleliabilitiesGross_c114817e-ab4f-442a-a321-ec46888050cb" xlink:href="itri-20240930.xsd#itri_FinitelivedintangibleliabilitiesGross"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_6e72c2bc-087b-4ed8-b1fa-19536d1f65a3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_ac48abcd-fb33-4bc9-9d5b-f3ed81d5ef42" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_ac48abcd-fb33-4bc9-9d5b-f3ed81d5ef42" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_e3f144fd-512e-4ed8-86ea-c01fa0f5e363" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_a5ec6624-eec2-45ca-b986-850760015dbf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_e3f144fd-512e-4ed8-86ea-c01fa0f5e363" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/ScheduleofGoodwillAllocatedtoReportingSegmentsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#ScheduleofGoodwillAllocatedtoReportingSegmentsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ScheduleofGoodwillAllocatedtoReportingSegmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_36d87af4-df4a-4f98-a88d-5241bec89ed3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_49b8ae12-387b-4301-be10-7b2a000d9eff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_36d87af4-df4a-4f98-a88d-5241bec89ed3" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_49b8ae12-387b-4301-be10-7b2a000d9eff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_c2ccebb7-0ce2-4494-b5d3-91af297b115d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_49b8ae12-387b-4301-be10-7b2a000d9eff" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_c2ccebb7-0ce2-4494-b5d3-91af297b115d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c2ccebb7-0ce2-4494-b5d3-91af297b115d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c2ccebb7-0ce2-4494-b5d3-91af297b115d" xlink:to="loc_us-gaap_SegmentDomain_c2ccebb7-0ce2-4494-b5d3-91af297b115d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ccc83cde-2ce1-4137-9e89-247b8d7b3388" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c2ccebb7-0ce2-4494-b5d3-91af297b115d" xlink:to="loc_us-gaap_SegmentDomain_ccc83cde-2ce1-4137-9e89-247b8d7b3388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_DeviceSolutionsMember_787cf250-151d-4743-9242-465fad6b1f2f" xlink:href="itri-20240930.xsd#itri_DeviceSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ccc83cde-2ce1-4137-9e89-247b8d7b3388" xlink:to="loc_itri_DeviceSolutionsMember_787cf250-151d-4743-9242-465fad6b1f2f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_NetworkedSolutionsSegmentMember_645462ab-c5a0-4b53-b765-fb51eb1ec213" xlink:href="itri-20240930.xsd#itri_NetworkedSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ccc83cde-2ce1-4137-9e89-247b8d7b3388" xlink:to="loc_itri_NetworkedSolutionsSegmentMember_645462ab-c5a0-4b53-b765-fb51eb1ec213" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OutcomesSegmentMember_8b10b310-03dc-4cdc-bc88-228f56d25f3e" xlink:href="itri-20240930.xsd#itri_OutcomesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ccc83cde-2ce1-4137-9e89-247b8d7b3388" xlink:to="loc_itri_OutcomesSegmentMember_8b10b310-03dc-4cdc-bc88-228f56d25f3e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_ca8a87bb-b2cf-41fb-87f9-3626001c0415" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_36d87af4-df4a-4f98-a88d-5241bec89ed3" xlink:to="loc_us-gaap_GoodwillRollForward_ca8a87bb-b2cf-41fb-87f9-3626001c0415" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_0487cc05-8593-4326-8888-1d9d21665b3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_ca8a87bb-b2cf-41fb-87f9-3626001c0415" xlink:to="loc_us-gaap_Goodwill_0487cc05-8593-4326-8888-1d9d21665b3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_7ccb947b-cd2e-48bf-9196-720e538f0efd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_ca8a87bb-b2cf-41fb-87f9-3626001c0415" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_7ccb947b-cd2e-48bf-9196-720e538f0efd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_c1ec68a2-671f-40ae-a172-227c2ad89128" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_ca8a87bb-b2cf-41fb-87f9-3626001c0415" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_c1ec68a2-671f-40ae-a172-227c2ad89128" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_dbc65b1a-bbc4-43ce-9c96-124038eaaf0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DebtScheduleofDebtComponentsofBorrowingDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DebtScheduleofDebtComponentsofBorrowingDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DebtScheduleofDebtComponentsofBorrowingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3a23b3a1-bd9e-4be6-bf7d-96a93401d5b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_DebtInstrumentTable_3a23b3a1-bd9e-4be6-bf7d-96a93401d5b9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_d82b5b17-baeb-4d53-ab44-3c8147fcad33" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3a23b3a1-bd9e-4be6-bf7d-96a93401d5b9" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_d82b5b17-baeb-4d53-ab44-3c8147fcad33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_d82b5b17-baeb-4d53-ab44-3c8147fcad33_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d82b5b17-baeb-4d53-ab44-3c8147fcad33" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_d82b5b17-baeb-4d53-ab44-3c8147fcad33_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1551d654-10d2-4c57-8c52-0a5f7f696407" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d82b5b17-baeb-4d53-ab44-3c8147fcad33" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1551d654-10d2-4c57-8c52-0a5f7f696407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_d2d3ac67-cbc3-4e7e-9086-8cdf75434de9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1551d654-10d2-4c57-8c52-0a5f7f696407" xlink:to="loc_us-gaap_LineOfCreditMember_d2d3ac67-cbc3-4e7e-9086-8cdf75434de9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_0e196331-5622-4afd-b486-523e119057b8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1551d654-10d2-4c57-8c52-0a5f7f696407" xlink:to="loc_us-gaap_SecuredDebtMember_0e196331-5622-4afd-b486-523e119057b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_9bbf1503-c65e-4993-808c-59d10e41ea03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1551d654-10d2-4c57-8c52-0a5f7f696407" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_9bbf1503-c65e-4993-808c-59d10e41ea03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_600efe51-4459-4960-bbf3-b273a52c259d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_LineOfCredit_600efe51-4459-4960-bbf3-b273a52c259d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebt_38b09572-3253-40bb-8de1-6c338dec19ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_ConvertibleDebt_38b09572-3253-40bb-8de1-6c338dec19ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_2adcaa21-d95f-454f-835a-af6677068ff7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_LongTermDebt_2adcaa21-d95f-454f-835a-af6677068ff7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_28e3a486-7223-4e53-9daf-0b74f9374bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_28e3a486-7223-4e53-9daf-0b74f9374bf9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_78413771-2725-4499-acf7-81642c2faee6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_868c53c0-eb80-48ea-ac30-01011d8dfdf3" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_78413771-2725-4499-acf7-81642c2faee6" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DebtCreditFacilityAdditionalInformationDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DebtCreditFacilityAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DebtCreditFacilityAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_898cd643-6ceb-44f8-8640-c42c54def973" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_898cd643-6ceb-44f8-8640-c42c54def973" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_898cd643-6ceb-44f8-8640-c42c54def973_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_898cd643-6ceb-44f8-8640-c42c54def973" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_898cd643-6ceb-44f8-8640-c42c54def973_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_898cd643-6ceb-44f8-8640-c42c54def973" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_UsdDenominatedTermLoanMember_920a6d2f-0bbb-4e93-969d-8eb115cfdbe7" xlink:href="itri-20240930.xsd#itri_UsdDenominatedTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:to="loc_itri_UsdDenominatedTermLoanMember_920a6d2f-0bbb-4e93-969d-8eb115cfdbe7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StandbyLettersOfCreditMember_d71cb768-0ea7-4245-9680-7721c1ae5329" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StandbyLettersOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:to="loc_us-gaap_StandbyLettersOfCreditMember_d71cb768-0ea7-4245-9680-7721c1ae5329" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_c4f4f052-2c54-48f0-a459-ce725dab21d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_c4f4f052-2c54-48f0-a459-ce725dab21d4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_8ce33f18-5f4f-4f24-8abb-7cbdeeef4241" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:to="loc_us-gaap_LineOfCreditMember_8ce33f18-5f4f-4f24-8abb-7cbdeeef4241" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_cb6dc8ea-e788-49ad-8109-e01aa7b5c667" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_c88d559a-bacd-4659-bde3-292ab01c362c" xlink:to="loc_us-gaap_SecuredDebtMember_cb6dc8ea-e788-49ad-8109-e01aa7b5c667" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_9666265f-1494-43e4-8b80-48c59038a0e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:to="loc_us-gaap_VariableRateAxis_9666265f-1494-43e4-8b80-48c59038a0e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_9666265f-1494-43e4-8b80-48c59038a0e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_9666265f-1494-43e4-8b80-48c59038a0e0" xlink:to="loc_us-gaap_VariableRateDomain_9666265f-1494-43e4-8b80-48c59038a0e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_9666265f-1494-43e4-8b80-48c59038a0e0" xlink:to="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsEffectiveSwapRateMember_1706cde7-b0eb-4396-8257-49e5e4df1a8e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FederalFundsEffectiveSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_us-gaap_FederalFundsEffectiveSwapRateMember_1706cde7-b0eb-4396-8257-49e5e4df1a8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AlternateBaseRate3Member_68b9e6ce-7574-4502-af2b-2406872abeea" xlink:href="itri-20240930.xsd#itri_AlternateBaseRate3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_AlternateBaseRate3Member_68b9e6ce-7574-4502-af2b-2406872abeea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LondonInterbankOfferedRateMember_6ce6d271-ab8d-4b94-a47e-eb422548628b" xlink:href="itri-20240930.xsd#itri_LondonInterbankOfferedRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_LondonInterbankOfferedRateMember_6ce6d271-ab8d-4b94-a47e-eb422548628b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_EURIBORMember_9e4448f0-8981-49ee-9eab-fda1f25be012" xlink:href="itri-20240930.xsd#itri_EURIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_EURIBORMember_9e4448f0-8981-49ee-9eab-fda1f25be012" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AlternateBaseRateMember_7d27bd92-6d45-42cf-9b02-fe2cb2307e38" xlink:href="itri-20240930.xsd#itri_AlternateBaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_AlternateBaseRateMember_7d27bd92-6d45-42cf-9b02-fe2cb2307e38" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AlternateBaseRate1Member_158dcaa8-c6b5-4471-a251-125944a42e71" xlink:href="itri-20240930.xsd#itri_AlternateBaseRate1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_AlternateBaseRate1Member_158dcaa8-c6b5-4471-a251-125944a42e71" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AlternateBaseRate2Member_95bb45a8-97e3-4e48-bb91-c1eccdd47166" xlink:href="itri-20240930.xsd#itri_AlternateBaseRate2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_7f5ea37d-a2f2-4ab1-9d0f-702e1773689c" xlink:to="loc_itri_AlternateBaseRate2Member_95bb45a8-97e3-4e48-bb91-c1eccdd47166" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a72b6110-e481-4f60-82e4-32b18676e75f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a72b6110-e481-4f60-82e4-32b18676e75f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_a72b6110-e481-4f60-82e4-32b18676e75f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a72b6110-e481-4f60-82e4-32b18676e75f" xlink:to="loc_us-gaap_LossContingencyNatureDomain_a72b6110-e481-4f60-82e4-32b18676e75f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_03f5ab48-e1d9-439a-b5a8-db4469fe9984" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a72b6110-e481-4f60-82e4-32b18676e75f" xlink:to="loc_us-gaap_LossContingencyNatureDomain_03f5ab48-e1d9-439a-b5a8-db4469fe9984" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CreditFacilityMember_3d8b2cbe-a843-496d-8174-6b33d9c07c14" xlink:href="itri-20240930.xsd#itri_CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_03f5ab48-e1d9-439a-b5a8-db4469fe9984" xlink:to="loc_itri_CreditFacilityMember_3d8b2cbe-a843-496d-8174-6b33d9c07c14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_eafe10fc-a28a-4b03-85a0-ad1168d6239a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:to="loc_srt_RangeAxis_eafe10fc-a28a-4b03-85a0-ad1168d6239a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_eafe10fc-a28a-4b03-85a0-ad1168d6239a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_eafe10fc-a28a-4b03-85a0-ad1168d6239a" xlink:to="loc_srt_RangeMember_eafe10fc-a28a-4b03-85a0-ad1168d6239a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fd696d85-ec2b-4851-abd7-96d0956e5646" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_eafe10fc-a28a-4b03-85a0-ad1168d6239a" xlink:to="loc_srt_RangeMember_fd696d85-ec2b-4851-abd7-96d0956e5646" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_21b5001a-83bc-463d-98ed-f0bc2cd73c2e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fd696d85-ec2b-4851-abd7-96d0956e5646" xlink:to="loc_srt_MinimumMember_21b5001a-83bc-463d-98ed-f0bc2cd73c2e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_ef975414-90ef-4821-ac11-b7eaa0b0eedf" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fd696d85-ec2b-4851-abd7-96d0956e5646" xlink:to="loc_srt_MaximumMember_ef975414-90ef-4821-ac11-b7eaa0b0eedf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_d09642ab-4004-484b-bfba-8e43f45641b5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_dca80119-096d-459f-b647-da17b2e8400e" xlink:to="loc_us-gaap_CreditFacilityAxis_d09642ab-4004-484b-bfba-8e43f45641b5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_d09642ab-4004-484b-bfba-8e43f45641b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_d09642ab-4004-484b-bfba-8e43f45641b5" xlink:to="loc_us-gaap_CreditFacilityDomain_d09642ab-4004-484b-bfba-8e43f45641b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_ccb7ac44-7a5c-4d7d-a9a1-4fc02c95a4d2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_d09642ab-4004-484b-bfba-8e43f45641b5" xlink:to="loc_us-gaap_CreditFacilityDomain_ccb7ac44-7a5c-4d7d-a9a1-4fc02c95a4d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2018CreditFacilityMember_d6bcde33-b9a9-4402-8d33-e6ec5a41405d" xlink:href="itri-20240930.xsd#itri_A2018CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_ccb7ac44-7a5c-4d7d-a9a1-4fc02c95a4d2" xlink:to="loc_itri_A2018CreditFacilityMember_d6bcde33-b9a9-4402-8d33-e6ec5a41405d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_e9e79af5-d0ab-494b-b6da-76adafffc59e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_e9e79af5-d0ab-494b-b6da-76adafffc59e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_26594a73-2758-4e8e-8928-e71f2ab9821b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_26594a73-2758-4e8e-8928-e71f2ab9821b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCollateral_6b575058-0271-444c-8f17-fface6302a2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_DebtInstrumentCollateral_6b575058-0271-444c-8f17-fface6302a2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_ac7e6520-abe0-49ff-a70c-8f2b47f5654d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_ac7e6520-abe0-49ff-a70c-8f2b47f5654d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_32ec84fd-25f1-4382-acc9-0b4a3ade6a0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_LineOfCredit_32ec84fd-25f1-4382-acc9-0b4a3ade6a0e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_50c97f37-0ed7-4a27-9f6d-6fe6ff003479" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_50c97f37-0ed7-4a27-9f6d-6fe6ff003479" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_243398b0-ad4c-4cf7-8580-854f042a96a7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_243398b0-ad4c-4cf7-8580-854f042a96a7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_f1b32e3c-5dfb-4f54-ad7f-b5dd28d2aa3f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentDescriptionOfVariableRateBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3ab1029e-547a-4d7a-b64e-afb74d496314" xlink:to="loc_us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_f1b32e3c-5dfb-4f54-ad7f-b5dd28d2aa3f" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DebtInterestCostAmendmentDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DebtInterestCostAmendmentDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DebtInterestCostAmendmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_26695b76-63cf-4bfc-8a15-c57c098cf22b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_43fd534d-a6d4-416a-adbb-19842e01c733" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_26695b76-63cf-4bfc-8a15-c57c098cf22b" xlink:to="loc_us-gaap_DebtInstrumentTable_43fd534d-a6d4-416a-adbb-19842e01c733" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_7569fb89-eed0-4074-8854-a0c19de7bfba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_43fd534d-a6d4-416a-adbb-19842e01c733" xlink:to="loc_us-gaap_CreditFacilityAxis_7569fb89-eed0-4074-8854-a0c19de7bfba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_7569fb89-eed0-4074-8854-a0c19de7bfba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_7569fb89-eed0-4074-8854-a0c19de7bfba" xlink:to="loc_us-gaap_CreditFacilityDomain_7569fb89-eed0-4074-8854-a0c19de7bfba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_7569fb89-eed0-4074-8854-a0c19de7bfba" xlink:to="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanFourMember_d2570861-6bd0-4841-b956-c8a324496228" xlink:href="itri-20240930.xsd#itri_IndebtednessToAdjustedEbitdaRatioGreaterThanFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:to="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanFourMember_d2570861-6bd0-4841-b956-c8a324496228" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanThreePointFiveOrLessThanFourMember_6a7bab6c-2863-4e2a-9190-2c1de37680d0" xlink:href="itri-20240930.xsd#itri_IndebtednessToAdjustedEbitdaRatioGreaterThanThreePointFiveOrLessThanFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:to="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanThreePointFiveOrLessThanFourMember_6a7bab6c-2863-4e2a-9190-2c1de37680d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanTwoPointFiveOrLessThanThreePointFiveMember_53dd21a4-a144-40b5-8fd2-d24cee38e0c3" xlink:href="itri-20240930.xsd#itri_IndebtednessToAdjustedEbitdaRatioGreaterThanTwoPointFiveOrLessThanThreePointFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:to="loc_itri_IndebtednessToAdjustedEbitdaRatioGreaterThanTwoPointFiveOrLessThanThreePointFiveMember_53dd21a4-a144-40b5-8fd2-d24cee38e0c3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_IndebtednessToAdjustedEbitdaRatioLessThanOrEqualTo2PointFiveMember_5796a713-c701-496c-b6e4-6fed9a8f6248" xlink:href="itri-20240930.xsd#itri_IndebtednessToAdjustedEbitdaRatioLessThanOrEqualTo2PointFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_2b675db4-00a0-4cf7-9699-531272c68e90" xlink:to="loc_itri_IndebtednessToAdjustedEbitdaRatioLessThanOrEqualTo2PointFiveMember_5796a713-c701-496c-b6e4-6fed9a8f6248" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_43fd534d-a6d4-416a-adbb-19842e01c733" xlink:to="loc_us-gaap_VariableRateAxis_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f" xlink:to="loc_us-gaap_VariableRateDomain_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_91e9e93e-ed77-450b-bb06-74b68110bed4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_bdb9ef9e-12ac-40fe-8fcd-4f8c3d87762f" xlink:to="loc_us-gaap_VariableRateDomain_91e9e93e-ed77-450b-bb06-74b68110bed4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_SecuredOvernightFinancingRateSOFRMember_571287c1-19f9-47ab-8da5-260687ac8e09" xlink:href="itri-20240930.xsd#itri_SecuredOvernightFinancingRateSOFRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_91e9e93e-ed77-450b-bb06-74b68110bed4" xlink:to="loc_itri_SecuredOvernightFinancingRateSOFRMember_571287c1-19f9-47ab-8da5-260687ac8e09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LineOfCreditFacilityInterestCostBasisPoints_9b6924ef-18f0-4e10-a8ed-baad78eab1b6" xlink:href="itri-20240930.xsd#itri_LineOfCreditFacilityInterestCostBasisPoints"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_26695b76-63cf-4bfc-8a15-c57c098cf22b" xlink:to="loc_itri_LineOfCreditFacilityInterestCostBasisPoints_9b6924ef-18f0-4e10-a8ed-baad78eab1b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LineOfCreditFacilityCommitmentFeeOnCreditFacilityBasisPoints_2fec94e0-4ff6-4cc4-87c6-255c01383991" xlink:href="itri-20240930.xsd#itri_LineOfCreditFacilityCommitmentFeeOnCreditFacilityBasisPoints"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_26695b76-63cf-4bfc-8a15-c57c098cf22b" xlink:to="loc_itri_LineOfCreditFacilityCommitmentFeeOnCreditFacilityBasisPoints_2fec94e0-4ff6-4cc4-87c6-255c01383991" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DebtConvertibleNoteAdditionalInformationDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DebtConvertibleNoteAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DebtConvertibleNoteAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_bb97a9a2-d434-4ba2-bb18-2f753cf44280" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:to="loc_us-gaap_DebtInstrumentAxis_bb97a9a2-d434-4ba2-bb18-2f753cf44280" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_bb97a9a2-d434-4ba2-bb18-2f753cf44280_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_bb97a9a2-d434-4ba2-bb18-2f753cf44280" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_bb97a9a2-d434-4ba2-bb18-2f753cf44280_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8ac4e816-8971-441c-b8f8-424958fa1c70" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_bb97a9a2-d434-4ba2-bb18-2f753cf44280" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8ac4e816-8971-441c-b8f8-424958fa1c70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2021NotesMember_589b584d-6b57-4f06-bff3-cb441b607c3d" xlink:href="itri-20240930.xsd#itri_A2021NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8ac4e816-8971-441c-b8f8-424958fa1c70" xlink:to="loc_itri_A2021NotesMember_589b584d-6b57-4f06-bff3-cb441b607c3d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2024NotesMember_24409280-3603-4655-8d8f-e7feb94e3769" xlink:href="itri-20240930.xsd#itri_A2024NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_8ac4e816-8971-441c-b8f8-424958fa1c70" xlink:to="loc_itri_A2024NotesMember_24409280-3603-4655-8d8f-e7feb94e3769" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_0a52f3d2-5648-4940-b608-bfcc425d956c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_0a52f3d2-5648-4940-b608-bfcc425d956c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_0a52f3d2-5648-4940-b608-bfcc425d956c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0a52f3d2-5648-4940-b608-bfcc425d956c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_0a52f3d2-5648-4940-b608-bfcc425d956c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1dfb48da-3baf-48f2-9941-0ee55de4508e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0a52f3d2-5648-4940-b608-bfcc425d956c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1dfb48da-3baf-48f2-9941-0ee55de4508e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_ba3a8ef9-2105-463c-90ae-3aa74fde2687" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1dfb48da-3baf-48f2-9941-0ee55de4508e" xlink:to="loc_us-gaap_ConvertibleDebtMember_ba3a8ef9-2105-463c-90ae-3aa74fde2687" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_b32273cc-5166-4b3a-ae7e-315e623ed162" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_b32273cc-5166-4b3a-ae7e-315e623ed162" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_b32273cc-5166-4b3a-ae7e-315e623ed162_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_b32273cc-5166-4b3a-ae7e-315e623ed162" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_b32273cc-5166-4b3a-ae7e-315e623ed162_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_b0f3b1cb-e155-4a0d-8b37-7d5271f7e8dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_b32273cc-5166-4b3a-ae7e-315e623ed162" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_b0f3b1cb-e155-4a0d-8b37-7d5271f7e8dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_625c785f-59cc-4457-9e05-77a85959530b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPeriodFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_b0f3b1cb-e155-4a0d-8b37-7d5271f7e8dd" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_625c785f-59cc-4457-9e05-77a85959530b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b83f8b6c-dca2-45c8-b06f-09031dfc82fb" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f569ae9b-194b-436e-8f55-0a8454911a2d" xlink:to="loc_srt_RangeAxis_b83f8b6c-dca2-45c8-b06f-09031dfc82fb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b83f8b6c-dca2-45c8-b06f-09031dfc82fb_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b83f8b6c-dca2-45c8-b06f-09031dfc82fb" xlink:to="loc_srt_RangeMember_b83f8b6c-dca2-45c8-b06f-09031dfc82fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ea15cffe-0c41-483d-8b67-eaa6b14da321" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b83f8b6c-dca2-45c8-b06f-09031dfc82fb" xlink:to="loc_srt_RangeMember_ea15cffe-0c41-483d-8b67-eaa6b14da321" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_36b0dd31-ec95-4a02-adc2-08bd1fae1770" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ea15cffe-0c41-483d-8b67-eaa6b14da321" xlink:to="loc_srt_MaximumMember_36b0dd31-ec95-4a02-adc2-08bd1fae1770" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebt_8a51de20-9dea-4449-9f4a-5833544409e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_ConvertibleDebt_8a51de20-9dea-4449-9f4a-5833544409e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromConvertibleDebt_12739ef6-d5a0-4bfc-824b-0a7d05154dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_ProceedsFromConvertibleDebt_12739ef6-d5a0-4bfc-824b-0a7d05154dd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_9b159bd1-674b-467b-8ea7-61c2ed0d2bba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionPrice1_9b159bd1-674b-467b-8ea7-61c2ed0d2bba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_59089734-7c6a-437c-9925-1df0a3d36eed" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_59089734-7c6a-437c-9925-1df0a3d36eed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_51a61987-9c13-490a-8455-e3346ead1e52" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_51a61987-9c13-490a-8455-e3346ead1e52" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_8a6022f4-9cc3-4a34-999e-41f5c8c44160" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_54aecbe1-b9d1-4f03-9ff4-cb99d2714a7b" xlink:to="loc_us-gaap_DebtInstrumentConvertibleConversionRatio1_8a6022f4-9cc3-4a34-999e-41f5c8c44160" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DerivativeFinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_f9025332-cee9-499b-b925-ae4c9b38c17f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_837b34a3-1d01-4926-97ed-51100254925c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_f9025332-cee9-499b-b925-ae4c9b38c17f" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_837b34a3-1d01-4926-97ed-51100254925c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_546ca553-111d-4efe-9a9d-cc6122a331ee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_837b34a3-1d01-4926-97ed-51100254925c" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_546ca553-111d-4efe-9a9d-cc6122a331ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_546ca553-111d-4efe-9a9d-cc6122a331ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_546ca553-111d-4efe-9a9d-cc6122a331ee" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_546ca553-111d-4efe-9a9d-cc6122a331ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_80d6ebfe-3e94-4b15-b012-2c7e25312112" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_546ca553-111d-4efe-9a9d-cc6122a331ee" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_80d6ebfe-3e94-4b15-b012-2c7e25312112" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForwardContractsMember_4f7900e7-b1d7-48e3-91ec-47241be7d8e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForwardContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_80d6ebfe-3e94-4b15-b012-2c7e25312112" xlink:to="loc_us-gaap_ForwardContractsMember_4f7900e7-b1d7-48e3-91ec-47241be7d8e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_98b43e29-1493-48f0-ad06-28165f818079" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_80d6ebfe-3e94-4b15-b012-2c7e25312112" xlink:to="loc_us-gaap_ForeignExchangeContractMember_98b43e29-1493-48f0-ad06-28165f818079" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_90b100dd-dbff-4d1b-9c87-685f98fb9389" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_837b34a3-1d01-4926-97ed-51100254925c" xlink:to="loc_srt_RangeAxis_90b100dd-dbff-4d1b-9c87-685f98fb9389" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_90b100dd-dbff-4d1b-9c87-685f98fb9389_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_90b100dd-dbff-4d1b-9c87-685f98fb9389" xlink:to="loc_srt_RangeMember_90b100dd-dbff-4d1b-9c87-685f98fb9389_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_53585074-888c-4c2e-bd24-24c31ca6f131" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_90b100dd-dbff-4d1b-9c87-685f98fb9389" xlink:to="loc_srt_RangeMember_53585074-888c-4c2e-bd24-24c31ca6f131" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_5f4c27c3-14e2-460b-98bd-b290390fc236" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_53585074-888c-4c2e-bd24-24c31ca6f131" xlink:to="loc_srt_MinimumMember_5f4c27c3-14e2-460b-98bd-b290390fc236" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d11cc723-b314-4441-a89c-b2eb04870245" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_53585074-888c-4c2e-bd24-24c31ca6f131" xlink:to="loc_srt_MaximumMember_d11cc723-b314-4441-a89c-b2eb04870245" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_837b34a3-1d01-4926-97ed-51100254925c" xlink:to="loc_us-gaap_HedgingDesignationAxis_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6" xlink:to="loc_us-gaap_HedgingDesignationDomain_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_d74a2eaa-a15f-4b07-9b1f-18158629d53d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_cd5022d2-7e35-4f4e-bf59-59f2dbf4d8b6" xlink:to="loc_us-gaap_HedgingDesignationDomain_d74a2eaa-a15f-4b07-9b1f-18158629d53d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_0112cbb5-279c-48ba-b043-de8806670f93" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_d74a2eaa-a15f-4b07-9b1f-18158629d53d" xlink:to="loc_us-gaap_NondesignatedMember_0112cbb5-279c-48ba-b043-de8806670f93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_02b3a632-8f30-4b34-87b2-a98f3f48f34f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_f9025332-cee9-499b-b925-ae4c9b38c17f" xlink:to="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_02b3a632-8f30-4b34-87b2-a98f3f48f34f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_f028d70f-7069-4f0a-b597-ff6f76be8098" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_f9025332-cee9-499b-b925-ae4c9b38c17f" xlink:to="loc_us-gaap_DerivativeNotionalAmount_f028d70f-7069-4f0a-b597-ff6f76be8098" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_52a5525e-9385-49a2-bd9c-d83696bb9955" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_52a5525e-9385-49a2-bd9c-d83696bb9955" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_9950ae67-1421-4c80-9412-4a8a8a980844" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_52a5525e-9385-49a2-bd9c-d83696bb9955" xlink:to="loc_us-gaap_PlanNameAxis_9950ae67-1421-4c80-9412-4a8a8a980844" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_9950ae67-1421-4c80-9412-4a8a8a980844_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_9950ae67-1421-4c80-9412-4a8a8a980844" xlink:to="loc_us-gaap_PlanNameDomain_9950ae67-1421-4c80-9412-4a8a8a980844_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_7b81864b-7d47-42e8-abad-5b80e2b65565" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_9950ae67-1421-4c80-9412-4a8a8a980844" xlink:to="loc_us-gaap_PlanNameDomain_7b81864b-7d47-42e8-abad-5b80e2b65565" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LongTermPerformanceRestrictedStockAwardMember_be5d29ae-79e7-479f-8453-e2450a331873" xlink:href="itri-20240930.xsd#itri_LongTermPerformanceRestrictedStockAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_7b81864b-7d47-42e8-abad-5b80e2b65565" xlink:to="loc_itri_LongTermPerformanceRestrictedStockAwardMember_be5d29ae-79e7-479f-8453-e2450a331873" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_StockIncentivePlanMember_df6ac6e5-f9fa-473c-89fe-c78d457b1f29" xlink:href="itri-20240930.xsd#itri_StockIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_7b81864b-7d47-42e8-abad-5b80e2b65565" xlink:to="loc_itri_StockIncentivePlanMember_df6ac6e5-f9fa-473c-89fe-c78d457b1f29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_52a5525e-9385-49a2-bd9c-d83696bb9955" xlink:to="loc_us-gaap_AwardTypeAxis_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9689d52c-110f-4ec2-9b19-7dfdf4fb00a8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_3f1b7373-9d27-4eb0-ab1c-7604f7c8249f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:to="loc_us-gaap_EmployeeStockOptionMember_3f1b7373-9d27-4eb0-ab1c-7604f7c8249f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LongTermPerformanceRestrictedStockAwardMember_644bab3e-d8f5-4536-9043-1986049fb115" xlink:href="itri-20240930.xsd#itri_LongTermPerformanceRestrictedStockAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:to="loc_itri_LongTermPerformanceRestrictedStockAwardMember_644bab3e-d8f5-4536-9043-1986049fb115" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_a5f84338-7852-4473-8d0d-34b548ceebd3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_a5f84338-7852-4473-8d0d-34b548ceebd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PhantomShareUnitsPSUsMember_7f6f6a0a-6eeb-4c20-b658-f86e65bde346" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PhantomShareUnitsPSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:to="loc_us-gaap_PhantomShareUnitsPSUsMember_7f6f6a0a-6eeb-4c20-b658-f86e65bde346" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_e55b528f-c083-4555-80c4-15b726472af3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_56bb201e-1bc5-49e0-aad0-5120b664bb5c" xlink:to="loc_us-gaap_EmployeeStockMember_e55b528f-c083-4555-80c4-15b726472af3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_41903c0d-5d69-43f5-a35b-2205416dec95" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_41903c0d-5d69-43f5-a35b-2205416dec95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_9f1a4710-79d2-42ce-ab54-5e2fbc3747a8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_9f1a4710-79d2-42ce-ab54-5e2fbc3747a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_Authorizedsharereservereductioninstockoptionsorshareappreciationrightsavailableforissueconversionratio_c9285137-f844-47ab-9711-f7f34cab7bfb" xlink:href="itri-20240930.xsd#itri_Authorizedsharereservereductioninstockoptionsorshareappreciationrightsavailableforissueconversionratio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_itri_Authorizedsharereservereductioninstockoptionsorshareappreciationrightsavailableforissueconversionratio_c9285137-f844-47ab-9711-f7f34cab7bfb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_Authorizedsharereservereductioninawardsotherthanstockoptionsorshareappreciationrightsavailableforissueconversionratio_bc958d0f-4dab-4c3e-b0a9-ffbdd628b50a" xlink:href="itri-20240930.xsd#itri_Authorizedsharereservereductioninawardsotherthanstockoptionsorshareappreciationrightsavailableforissueconversionratio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_itri_Authorizedsharereservereductioninawardsotherthanstockoptionsorshareappreciationrightsavailableforissueconversionratio_bc958d0f-4dab-4c3e-b0a9-ffbdd628b50a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_165e2fa3-86cc-4bdf-a1a1-ddf4d038f2a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_165e2fa3-86cc-4bdf-a1a1-ddf4d038f2a5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_d38fdb7a-f956-49c3-b850-29a9c7ef0ccb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_c3591c35-9e37-427f-a854-0cd2bd1ac3c7" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_d38fdb7a-f956-49c3-b850-29a9c7ef0ccb" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationExpenseandRelatedTaxBenefitDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationExpenseandRelatedTaxBenefitDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationExpenseandRelatedTaxBenefitDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d738595-3835-4900-a184-80b06bcff06e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d738595-3835-4900-a184-80b06bcff06e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_1ac32d7f-8187-4087-97d3-f33cac32e174" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d738595-3835-4900-a184-80b06bcff06e" xlink:to="loc_us-gaap_PlanNameAxis_1ac32d7f-8187-4087-97d3-f33cac32e174" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_1ac32d7f-8187-4087-97d3-f33cac32e174_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_1ac32d7f-8187-4087-97d3-f33cac32e174" xlink:to="loc_us-gaap_PlanNameDomain_1ac32d7f-8187-4087-97d3-f33cac32e174_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_149c4a2b-3929-483b-bbc8-e240e872bfe4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_1ac32d7f-8187-4087-97d3-f33cac32e174" xlink:to="loc_us-gaap_PlanNameDomain_149c4a2b-3929-483b-bbc8-e240e872bfe4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_StockIncentivePlanMember_47a34dbc-65a8-4700-b370-edd9ab8d6c91" xlink:href="itri-20240930.xsd#itri_StockIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_149c4a2b-3929-483b-bbc8-e240e872bfe4" xlink:to="loc_itri_StockIncentivePlanMember_47a34dbc-65a8-4700-b370-edd9ab8d6c91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_61c99558-44e2-4e82-a1ea-4eaee59a9e51" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d738595-3835-4900-a184-80b06bcff06e" xlink:to="loc_us-gaap_AwardTypeAxis_61c99558-44e2-4e82-a1ea-4eaee59a9e51" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61c99558-44e2-4e82-a1ea-4eaee59a9e51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_61c99558-44e2-4e82-a1ea-4eaee59a9e51" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61c99558-44e2-4e82-a1ea-4eaee59a9e51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_da1e02c6-17bf-4f62-a152-668a843fa23d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_61c99558-44e2-4e82-a1ea-4eaee59a9e51" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_da1e02c6-17bf-4f62-a152-668a843fa23d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PhantomShareUnitsPSUsMember_bd0133c1-7594-4f16-a997-c2bc891355cb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PhantomShareUnitsPSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_da1e02c6-17bf-4f62-a152-668a843fa23d" xlink:to="loc_us-gaap_PhantomShareUnitsPSUsMember_bd0133c1-7594-4f16-a997-c2bc891355cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockOptionPlanExpense_3601982a-723e-431e-ba52-376e9970eb0a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockOptionPlanExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_StockOptionPlanExpense_3601982a-723e-431e-ba52-376e9970eb0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockExpense_b282298f-b0e4-4533-93d2-48c46abcd8cc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_RestrictedStockExpense_b282298f-b0e4-4533-93d2-48c46abcd8cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_UnrestrictedStockAwardsCompensationExpense_07c64721-9f43-49b5-a71d-3e42c3d1631e" xlink:href="itri-20240930.xsd#itri_UnrestrictedStockAwardsCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_itri_UnrestrictedStockAwardsCompensationExpense_07c64721-9f43-49b5-a71d-3e42c3d1631e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_d2760d08-e4cd-412c-af05-14e8f01efc1f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_d2760d08-e4cd-412c-af05-14e8f01efc1f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1_6cba2389-1a87-454d-93e1-e8a1f2c0dd50" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1_6cba2389-1a87-454d-93e1-e8a1f2c0dd50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_88fc46a2-3ffc-40d0-8766-119c73553d01" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_99f654e7-a9ed-4860-aa6d-2764650f8285" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_88fc46a2-3ffc-40d0-8766-119c73553d01" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationStockOptionSummaryDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationStockOptionSummaryDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationStockOptionSummaryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe4be255-0dc8-4beb-a0bc-0b0ad1b527d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe4be255-0dc8-4beb-a0bc-0b0ad1b527d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_d9838953-928f-4c7a-addb-f24ba02e7880" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe4be255-0dc8-4beb-a0bc-0b0ad1b527d4" xlink:to="loc_us-gaap_AwardTypeAxis_d9838953-928f-4c7a-addb-f24ba02e7880" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d9838953-928f-4c7a-addb-f24ba02e7880_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_d9838953-928f-4c7a-addb-f24ba02e7880" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d9838953-928f-4c7a-addb-f24ba02e7880_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e0ce01b9-d3dd-4592-98f5-aff7569d43e7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_d9838953-928f-4c7a-addb-f24ba02e7880" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e0ce01b9-d3dd-4592-98f5-aff7569d43e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_2a050114-90fc-4e44-b0b4-dbe5c5c0b581" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e0ce01b9-d3dd-4592-98f5-aff7569d43e7" xlink:to="loc_us-gaap_EmployeeStockMember_2a050114-90fc-4e44-b0b4-dbe5c5c0b581" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_670ddc79-12e2-4ae7-97c5-3178956ed480" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e0ce01b9-d3dd-4592-98f5-aff7569d43e7" xlink:to="loc_us-gaap_EmployeeStockOptionMember_670ddc79-12e2-4ae7-97c5-3178956ed480" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_d0b6b28b-3a7e-41eb-ab79-34c17318aad5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_d0b6b28b-3a7e-41eb-ab79-34c17318aad5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_427ed975-0c15-4822-90f7-50c1149b79c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_427ed975-0c15-4822-90f7-50c1149b79c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_d77fbac8-8d54-4b9f-8cc0-39ad8e50ef3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_d77fbac8-8d54-4b9f-8cc0-39ad8e50ef3e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_dcc609a2-05db-4322-a6e4-fb5d32d73153" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_dcc609a2-05db-4322-a6e4-fb5d32d73153" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_a0838296-f6f6-48df-9d0c-07dea774faab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d76f0cc-1426-4ff9-b889-f89a3b019d3b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod_a0838296-f6f6-48df-9d0c-07dea774faab" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_e6337838-d077-48e5-b0b1-b82a3ce70f67" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_e8b264d5-0445-431a-accc-6ee558146fee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_e8b264d5-0445-431a-accc-6ee558146fee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2bad5efc-9ee2-4e22-be9d-1b5f320fd262" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2bad5efc-9ee2-4e22-be9d-1b5f320fd262" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_d8690b87-fba7-42be-8f26-305cadee3e9d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_d8690b87-fba7-42be-8f26-305cadee3e9d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_3d8ff4b8-5e17-4cf6-a2a1-0644c8ea21d9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_3d8ff4b8-5e17-4cf6-a2a1-0644c8ea21d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_1063c86a-a1d6-4b90-96d1-e5dfc7a3ea24" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_1063c86a-a1d6-4b90-96d1-e5dfc7a3ea24" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_88053fea-f1e1-407d-b6e1-102e53cf2b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_7acc6df9-98f9-46a5-81df-81f47ded512e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice_88053fea-f1e1-407d-b6e1-102e53cf2b4a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_9db00ea0-37e4-41cf-b0d9-e408347c8cad" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_26e995de-c54a-4d81-ba2f-ffd8366a2099" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_26e995de-c54a-4d81-ba2f-ffd8366a2099" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_232b92b7-a01d-4c97-ac8b-b1231458714b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_60c6fac9-dc75-4510-a653-71cd9d955c73" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_60c6fac9-dc75-4510-a653-71cd9d955c73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_5e9246f7-372d-4397-951d-103aea885a4d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_5e9246f7-372d-4397-951d-103aea885a4d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f922a84e-0696-4fe1-ac60-e1e24f61e2dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f922a84e-0696-4fe1-ac60-e1e24f61e2dd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_069eb826-5461-445b-92db-40a21523cce6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_069eb826-5461-445b-92db-40a21523cce6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_abdebb9d-d478-47f0-ba8e-0e1a42c0dcdd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_50fc874d-cb2c-4b28-b79a-cb52cd74747d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_828a4845-8d36-494e-b07c-69bfbdcd036d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_828a4845-8d36-494e-b07c-69bfbdcd036d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_f776db6f-f5f4-4307-9941-46ad6859e247" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_ab466854-be46-4d61-9c11-a08f94671423" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_f776db6f-f5f4-4307-9941-46ad6859e247" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationStockOptionBlackScholesOptionPricingModelAssumptionsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationStockOptionBlackScholesOptionPricingModelAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationStockOptionBlackScholesOptionPricingModelAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_31d95f62-0c62-47d1-8e32-3055539d82ac" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_94c43cc6-623f-4ebc-bb75-3af6ef32c583" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_31d95f62-0c62-47d1-8e32-3055539d82ac" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_94c43cc6-623f-4ebc-bb75-3af6ef32c583" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_72e2e921-a046-4dae-afca-a230ee6ac379" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_94c43cc6-623f-4ebc-bb75-3af6ef32c583" xlink:to="loc_us-gaap_AwardTypeAxis_72e2e921-a046-4dae-afca-a230ee6ac379" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_72e2e921-a046-4dae-afca-a230ee6ac379_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_72e2e921-a046-4dae-afca-a230ee6ac379" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_72e2e921-a046-4dae-afca-a230ee6ac379_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a0666a1c-c9c9-4c22-ace2-cc7204d89fb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_72e2e921-a046-4dae-afca-a230ee6ac379" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a0666a1c-c9c9-4c22-ace2-cc7204d89fb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_7017bba7-26a8-41f8-95fb-70fd0109ca3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a0666a1c-c9c9-4c22-ace2-cc7204d89fb7" xlink:to="loc_us-gaap_EmployeeStockOptionMember_7017bba7-26a8-41f8-95fb-70fd0109ca3e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_bb7e2c2b-c410-4e87-9840-b78f1ca75807" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_31d95f62-0c62-47d1-8e32-3055539d82ac" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_bb7e2c2b-c410-4e87-9840-b78f1ca75807" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_9fd3bfb9-a0a9-4253-988a-1cb4b935f744" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_31d95f62-0c62-47d1-8e32-3055539d82ac" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_9fd3bfb9-a0a9-4253-988a-1cb4b935f744" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_bbafb140-4cde-4212-939b-6cb64772e017" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_31d95f62-0c62-47d1-8e32-3055539d82ac" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_bbafb140-4cde-4212-939b-6cb64772e017" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationRestrictedStockUnitsSummaryDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationRestrictedStockUnitsSummaryDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationRestrictedStockUnitsSummaryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_cc54df3d-122b-40fc-8c0d-c411dd34a14c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1ff21836-d6e4-4c0f-b730-6af49d10d035" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_cc54df3d-122b-40fc-8c0d-c411dd34a14c" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1ff21836-d6e4-4c0f-b730-6af49d10d035" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_b6697faa-0efa-4fb6-b11b-139a58907c02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1ff21836-d6e4-4c0f-b730-6af49d10d035" xlink:to="loc_us-gaap_PlanNameAxis_b6697faa-0efa-4fb6-b11b-139a58907c02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b6697faa-0efa-4fb6-b11b-139a58907c02_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_b6697faa-0efa-4fb6-b11b-139a58907c02" xlink:to="loc_us-gaap_PlanNameDomain_b6697faa-0efa-4fb6-b11b-139a58907c02_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_caef45b6-da0a-4e9e-b482-82518808902a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_b6697faa-0efa-4fb6-b11b-139a58907c02" xlink:to="loc_us-gaap_PlanNameDomain_caef45b6-da0a-4e9e-b482-82518808902a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LongTermPerformanceRestrictedStockAwardMember_6abf017f-c3f2-4680-b6d2-1d997ea24d7b" xlink:href="itri-20240930.xsd#itri_LongTermPerformanceRestrictedStockAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_caef45b6-da0a-4e9e-b482-82518808902a" xlink:to="loc_itri_LongTermPerformanceRestrictedStockAwardMember_6abf017f-c3f2-4680-b6d2-1d997ea24d7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_9893c1bd-855c-48cb-b036-071a88525bf4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1ff21836-d6e4-4c0f-b730-6af49d10d035" xlink:to="loc_us-gaap_VestingAxis_9893c1bd-855c-48cb-b036-071a88525bf4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_9893c1bd-855c-48cb-b036-071a88525bf4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_9893c1bd-855c-48cb-b036-071a88525bf4" xlink:to="loc_us-gaap_VestingDomain_9893c1bd-855c-48cb-b036-071a88525bf4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_451379b7-e3ac-442e-bbba-321edb6c1e00" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_9893c1bd-855c-48cb-b036-071a88525bf4" xlink:to="loc_us-gaap_VestingDomain_451379b7-e3ac-442e-bbba-321edb6c1e00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_VestedAndReleasedMember_2f06e032-fa43-4b70-a4da-37bc23ac81d7" xlink:href="itri-20240930.xsd#itri_VestedAndReleasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_451379b7-e3ac-442e-bbba-321edb6c1e00" xlink:to="loc_itri_VestedAndReleasedMember_2f06e032-fa43-4b70-a4da-37bc23ac81d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_VestedButNotReleasedMember_5cbef984-03f3-4626-90ef-34ce996625b1" xlink:href="itri-20240930.xsd#itri_VestedButNotReleasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_451379b7-e3ac-442e-bbba-321edb6c1e00" xlink:to="loc_itri_VestedButNotReleasedMember_5cbef984-03f3-4626-90ef-34ce996625b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_69d5e297-fb56-4a58-b341-70f01b30d495" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_1ff21836-d6e4-4c0f-b730-6af49d10d035" xlink:to="loc_us-gaap_AwardTypeAxis_69d5e297-fb56-4a58-b341-70f01b30d495" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_69d5e297-fb56-4a58-b341-70f01b30d495_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_69d5e297-fb56-4a58-b341-70f01b30d495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_69d5e297-fb56-4a58-b341-70f01b30d495_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a6621384-eb0d-4224-b949-7479781d4505" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_69d5e297-fb56-4a58-b341-70f01b30d495" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a6621384-eb0d-4224-b949-7479781d4505" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_794be4b3-2068-4328-8219-4a7175eb110b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a6621384-eb0d-4224-b949-7479781d4505" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_794be4b3-2068-4328-8219-4a7175eb110b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_cc54df3d-122b-40fc-8c0d-c411dd34a14c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2119dd63-7738-4082-a656-f4ee3944eb2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2119dd63-7738-4082-a656-f4ee3944eb2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_8ea69bba-f5f1-47e1-8bea-8f5feb418518" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_8ea69bba-f5f1-47e1-8bea-8f5feb418518" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_329abc66-0cf8-4475-bedf-df2e89e68729" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_329abc66-0cf8-4475-bedf-df2e89e68729" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_9637bfb1-b3aa-4d18-bd47-0414e069170a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_9637bfb1-b3aa-4d18-bd47-0414e069170a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_b80ffcb6-91b4-427e-96f1-e7153cd3f92a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_SharesIssuedSharesShareBasedPaymentArrangementVestedButNotReleased_7f3237ac-c5c5-4864-81ad-018bd601a265" xlink:href="itri-20240930.xsd#itri_SharesIssuedSharesShareBasedPaymentArrangementVestedButNotReleased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_dc2d3e48-a238-41d9-98e6-5323ac714f68" xlink:to="loc_itri_SharesIssuedSharesShareBasedPaymentArrangementVestedButNotReleased_7f3237ac-c5c5-4864-81ad-018bd601a265" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_cc54df3d-122b-40fc-8c0d-c411dd34a14c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_4f8d6ab5-d22c-4556-86e3-03e3e3b663d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_4f8d6ab5-d22c-4556-86e3-03e3e3b663d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_5f5fddd1-70ed-4d94-8243-56bde2834cca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_5f5fddd1-70ed-4d94-8243-56bde2834cca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_cdc250f7-2a55-401a-b6e9-17abb841e402" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_cdc250f7-2a55-401a-b6e9-17abb841e402" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_472739d9-99b1-433d-a069-c45f54f1b743" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d32b6e9a-9697-46f8-8b69-b3623ace7788" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_472739d9-99b1-433d-a069-c45f54f1b743" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_d5bd7dc2-a3e6-4f74-8bdb-f51e96ef880f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_c0e4629c-61c1-4508-9c73-d7b7a9f97bd5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_cc54df3d-122b-40fc-8c0d-c411dd34a14c" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_c0e4629c-61c1-4508-9c73-d7b7a9f97bd5" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/StockBasedCompensationLongTermPerformanceRestrictedStockUnitAwardMonteCarloPricingModelAssumptionsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#StockBasedCompensationLongTermPerformanceRestrictedStockUnitAwardMonteCarloPricingModelAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/StockBasedCompensationLongTermPerformanceRestrictedStockUnitAwardMonteCarloPricingModelAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fb48b74-ea4c-41a0-be62-c0ce4d0e2a1e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fb48b74-ea4c-41a0-be62-c0ce4d0e2a1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_30d66f82-bf43-4208-9507-9a47bd5a54c0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fb48b74-ea4c-41a0-be62-c0ce4d0e2a1e" xlink:to="loc_us-gaap_AwardTypeAxis_30d66f82-bf43-4208-9507-9a47bd5a54c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_30d66f82-bf43-4208-9507-9a47bd5a54c0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_30d66f82-bf43-4208-9507-9a47bd5a54c0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_30d66f82-bf43-4208-9507-9a47bd5a54c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e2986d7b-dff9-44bc-881c-665ac911cfd5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_30d66f82-bf43-4208-9507-9a47bd5a54c0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e2986d7b-dff9-44bc-881c-665ac911cfd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_ffe3368f-53b4-40d0-bf1c-28e244fddac7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e2986d7b-dff9-44bc-881c-665ac911cfd5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_ffe3368f-53b4-40d0-bf1c-28e244fddac7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_73e25225-d79b-4212-8b59-ea3f5a47f43a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_6fb48b74-ea4c-41a0-be62-c0ce4d0e2a1e" xlink:to="loc_us-gaap_PlanNameAxis_73e25225-d79b-4212-8b59-ea3f5a47f43a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_73e25225-d79b-4212-8b59-ea3f5a47f43a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_73e25225-d79b-4212-8b59-ea3f5a47f43a" xlink:to="loc_us-gaap_PlanNameDomain_73e25225-d79b-4212-8b59-ea3f5a47f43a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_7c02a9c2-8ddf-4f52-9a2c-bdb83b3892d0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_73e25225-d79b-4212-8b59-ea3f5a47f43a" xlink:to="loc_us-gaap_PlanNameDomain_7c02a9c2-8ddf-4f52-9a2c-bdb83b3892d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LongTermPerformanceRestrictedStockAwardMember_a3dd7f88-c2b6-433b-9564-0e0e8a67b3aa" xlink:href="itri-20240930.xsd#itri_LongTermPerformanceRestrictedStockAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_7c02a9c2-8ddf-4f52-9a2c-bdb83b3892d0" xlink:to="loc_itri_LongTermPerformanceRestrictedStockAwardMember_a3dd7f88-c2b6-433b-9564-0e0e8a67b3aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_3b46b2c8-1a13-45fe-be3f-7a4d86225f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_3b46b2c8-1a13-45fe-be3f-7a4d86225f0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_cc704b8a-709d-4bed-9c81-7e3c2a06848b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_cc704b8a-709d-4bed-9c81-7e3c2a06848b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_cdd95fae-69b9-45c6-b1a4-552fff77c168" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_cdd95fae-69b9-45c6-b1a4-552fff77c168" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fead7923-b9e4-46ce-9bec-aa67afbe94c7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_9ff34898-8ce3-43bc-af3c-f3a82418ff14" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_fead7923-b9e4-46ce-9bec-aa67afbe94c7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationLineItems_3ffcdf72-5619-419e-bef3-c8a031269725" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExaminationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationTable_ef067339-6084-449f-9cc5-3dcb0b7ac824" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxExaminationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_3ffcdf72-5619-419e-bef3-c8a031269725" xlink:to="loc_us-gaap_IncomeTaxExaminationTable_ef067339-6084-449f-9cc5-3dcb0b7ac824" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_ef067339-6084-449f-9cc5-3dcb0b7ac824" xlink:to="loc_srt_RangeAxis_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97" xlink:to="loc_srt_RangeMember_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_30515316-b178-40ec-a729-d824de3f582f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_5df8f6e7-fd5f-4206-aeb0-2c5d0acc1b97" xlink:to="loc_srt_RangeMember_30515316-b178-40ec-a729-d824de3f582f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_12b45f12-5fcd-4dd4-aef3-9eb2b93ea171" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_30515316-b178-40ec-a729-d824de3f582f" xlink:to="loc_srt_MinimumMember_12b45f12-5fcd-4dd4-aef3-9eb2b93ea171" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_79c66216-5fe3-4e0e-8402-afee03331fc8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_30515316-b178-40ec-a729-d824de3f582f" xlink:to="loc_srt_MaximumMember_79c66216-5fe3-4e0e-8402-afee03331fc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_d8c9b74a-56a5-4f7a-82c2-bf80866736a0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_3ffcdf72-5619-419e-bef3-c8a031269725" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_d8c9b74a-56a5-4f7a-82c2-bf80866736a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_93ef2f7d-f90d-4ed3-a46f-4cce148a77d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_3ffcdf72-5619-419e-bef3-c8a031269725" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_93ef2f7d-f90d-4ed3-a46f-4cce148a77d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherTaxExpenseBenefit_b2fd52d3-d0d4-4562-a6e8-eccb0aa3de78" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_3ffcdf72-5619-419e-bef3-c8a031269725" xlink:to="loc_us-gaap_OtherTaxExpenseBenefit_b2fd52d3-d0d4-4562-a6e8-eccb0aa3de78" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/CommitmentsandContingenciesAvailableLinesofCreditOutstandingStandbyLetterofCreditsandBondsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#CommitmentsandContingenciesAvailableLinesofCreditOutstandingStandbyLetterofCreditsandBondsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/CommitmentsandContingenciesAvailableLinesofCreditOutstandingStandbyLetterofCreditsandBondsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_10053626-5976-48bf-ad2b-3901df02ad3d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_10053626-5976-48bf-ad2b-3901df02ad3d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_29104367-2faa-48bc-adf7-0fb5860db588" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_10053626-5976-48bf-ad2b-3901df02ad3d" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_29104367-2faa-48bc-adf7-0fb5860db588" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_29104367-2faa-48bc-adf7-0fb5860db588_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_29104367-2faa-48bc-adf7-0fb5860db588" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_29104367-2faa-48bc-adf7-0fb5860db588_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e90d1508-7e75-426c-8805-1a775f39b001" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_29104367-2faa-48bc-adf7-0fb5860db588" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e90d1508-7e75-426c-8805-1a775f39b001" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_4b08d6cc-7d59-4ff8-8d79-d8d4b57b9f36" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e90d1508-7e75-426c-8805-1a775f39b001" xlink:to="loc_us-gaap_LineOfCreditMember_4b08d6cc-7d59-4ff8-8d79-d8d4b57b9f36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_245d721b-21ce-4431-9701-aed91c6e5a96" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_10053626-5976-48bf-ad2b-3901df02ad3d" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_245d721b-21ce-4431-9701-aed91c6e5a96" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_245d721b-21ce-4431-9701-aed91c6e5a96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_245d721b-21ce-4431-9701-aed91c6e5a96" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_245d721b-21ce-4431-9701-aed91c6e5a96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_18baf4ad-702f-49f3-b1f7-2729f261ba46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_245d721b-21ce-4431-9701-aed91c6e5a96" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_18baf4ad-702f-49f3-b1f7-2729f261ba46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SuretyBondMember_3516a502-be41-4be0-95ae-9b8442247881" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SuretyBondMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_18baf4ad-702f-49f3-b1f7-2729f261ba46" xlink:to="loc_us-gaap_SuretyBondMember_3516a502-be41-4be0-95ae-9b8442247881" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_92b917f5-06ac-41a4-b792-c45fb13f4b52" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_10053626-5976-48bf-ad2b-3901df02ad3d" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_92b917f5-06ac-41a4-b792-c45fb13f4b52" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_92b917f5-06ac-41a4-b792-c45fb13f4b52_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_92b917f5-06ac-41a4-b792-c45fb13f4b52" xlink:to="loc_us-gaap_LossContingencyNatureDomain_92b917f5-06ac-41a4-b792-c45fb13f4b52_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_a5a889df-5fdf-48e1-8809-3cd7ca3daabf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_92b917f5-06ac-41a4-b792-c45fb13f4b52" xlink:to="loc_us-gaap_LossContingencyNatureDomain_a5a889df-5fdf-48e1-8809-3cd7ca3daabf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CreditFacilityMember_762a0c90-b41e-402d-8e72-b80cf5c6c91f" xlink:href="itri-20240930.xsd#itri_CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_a5a889df-5fdf-48e1-8809-3cd7ca3daabf" xlink:to="loc_itri_CreditFacilityMember_762a0c90-b41e-402d-8e72-b80cf5c6c91f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_UnsecuredMulticurrencyRevolvingLinesOfCreditMember_5a0dc50f-7673-474c-b08a-97acc0bd1901" xlink:href="itri-20240930.xsd#itri_UnsecuredMulticurrencyRevolvingLinesOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_a5a889df-5fdf-48e1-8809-3cd7ca3daabf" xlink:to="loc_itri_UnsecuredMulticurrencyRevolvingLinesOfCreditMember_5a0dc50f-7673-474c-b08a-97acc0bd1901" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a84d8231-46ff-400c-b4db-e9752f54a217" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a84d8231-46ff-400c-b4db-e9752f54a217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_439682f5-ec6e-4b8a-930c-90c938cb1a03" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_LineOfCredit_439682f5-ec6e-4b8a-930c-90c938cb1a03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_63e0dba7-f2a2-49da-8ff9-274b2b68ead0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_63e0dba7-f2a2-49da-8ff9-274b2b68ead0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_882a6475-aabb-438e-ab19-15da8435c2c3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_ShortTermBorrowings_882a6475-aabb-438e-ab19-15da8435c2c3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_e92e6786-2e74-4e15-909d-a266e915bbd5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_e92e6786-2e74-4e15-909d-a266e915bbd5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_LineofCreditFacilityRemainingcapacitytosupportlettersofcredit_fb7f16a4-df42-41b9-a92d-72d5ce711d82" xlink:href="itri-20240930.xsd#itri_LineofCreditFacilityRemainingcapacitytosupportlettersofcredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_itri_LineofCreditFacilityRemainingcapacitytosupportlettersofcredit_fb7f16a4-df42-41b9-a92d-72d5ce711d82" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_2d44c444-2293-4380-b8e6-a778c5a2b41c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_ca30e860-7023-4410-819a-0e61a69b011d" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_2d44c444-2293-4380-b8e6-a778c5a2b41c" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/RestructuringExpectedCostsRestructuringReservebyTypeofCostDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#RestructuringExpectedCostsRestructuringReservebyTypeofCostDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/RestructuringExpectedCostsRestructuringReservebyTypeofCostDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_f1e1a7ea-e37b-4ab0-98d4-dd6a4bb2c3f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_f1e1a7ea-e37b-4ab0-98d4-dd6a4bb2c3f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_d2340dc0-d387-4444-b45f-b9701401fc79" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_f1e1a7ea-e37b-4ab0-98d4-dd6a4bb2c3f0" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_d2340dc0-d387-4444-b45f-b9701401fc79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_d2340dc0-d387-4444-b45f-b9701401fc79_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_d2340dc0-d387-4444-b45f-b9701401fc79" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_d2340dc0-d387-4444-b45f-b9701401fc79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_a23cf2bc-25f5-4d13-959f-889c81bd4dc0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_d2340dc0-d387-4444-b45f-b9701401fc79" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_a23cf2bc-25f5-4d13-959f-889c81bd4dc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_9b559bdb-94ca-4abf-8b81-d5e4d473eab2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_a23cf2bc-25f5-4d13-959f-889c81bd4dc0" xlink:to="loc_us-gaap_EmployeeSeveranceMember_9b559bdb-94ca-4abf-8b81-d5e4d473eab2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember_3a7a4d04-ce88-4dba-b59e-69fea22b1c17" xlink:href="itri-20240930.xsd#itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_a23cf2bc-25f5-4d13-959f-889c81bd4dc0" xlink:to="loc_itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember_3a7a4d04-ce88-4dba-b59e-69fea22b1c17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRestructuringMember_34659b2e-e155-4757-8ae3-c2c820598db7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherRestructuringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_a23cf2bc-25f5-4d13-959f-889c81bd4dc0" xlink:to="loc_us-gaap_OtherRestructuringMember_34659b2e-e155-4757-8ae3-c2c820598db7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_f966acdd-d38c-4109-8e48-1976f81ed871" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_f1e1a7ea-e37b-4ab0-98d4-dd6a4bb2c3f0" xlink:to="loc_us-gaap_RestructuringPlanAxis_f966acdd-d38c-4109-8e48-1976f81ed871" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_f966acdd-d38c-4109-8e48-1976f81ed871_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_f966acdd-d38c-4109-8e48-1976f81ed871" xlink:to="loc_us-gaap_RestructuringPlanDomain_f966acdd-d38c-4109-8e48-1976f81ed871_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_7fd8330f-28c6-4833-a76c-330e078d804d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_f966acdd-d38c-4109-8e48-1976f81ed871" xlink:to="loc_us-gaap_RestructuringPlanDomain_7fd8330f-28c6-4833-a76c-330e078d804d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2023ProjectsMember_76913265-4c24-4ffa-a7ae-7df78e24f78c" xlink:href="itri-20240930.xsd#itri_A2023ProjectsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_7fd8330f-28c6-4833-a76c-330e078d804d" xlink:to="loc_itri_A2023ProjectsMember_76913265-4c24-4ffa-a7ae-7df78e24f78c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2021ProjectsMember_6770f586-9443-44d1-8944-a9f4721ffbf3" xlink:href="itri-20240930.xsd#itri_A2021ProjectsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_7fd8330f-28c6-4833-a76c-330e078d804d" xlink:to="loc_itri_A2021ProjectsMember_6770f586-9443-44d1-8944-a9f4721ffbf3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_f5990e3d-c11f-4ef0-8dd6-4f666301c86b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringAndRelatedCostExpectedCost1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_f5990e3d-c11f-4ef0-8dd6-4f666301c86b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_eb63a196-408d-4caa-a7a4-c79106fd163a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringAndRelatedCostCostIncurredToDate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:to="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_eb63a196-408d-4caa-a7a4-c79106fd163a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_bc503c30-9d06-4588-8758-62d5c100365a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:to="loc_us-gaap_RestructuringCharges_bc503c30-9d06-4588-8758-62d5c100365a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_78ac0685-a0b9-45a8-a35d-781c319c15f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_bacbe459-e5ac-4469-9a60-3ec48ec9ccc7" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_78ac0685-a0b9-45a8-a35d-781c319c15f6" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/RestructuringAdditionalInformationDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#RestructuringAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/RestructuringAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_954cfb69-2de4-4180-a001-c84072ba1df1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_fe241f08-58f7-4b37-b3b5-38397d7f3ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_954cfb69-2de4-4180-a001-c84072ba1df1" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_fe241f08-58f7-4b37-b3b5-38397d7f3ac7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_4d84557c-2e66-4d29-9eba-634283a920b5" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_fe241f08-58f7-4b37-b3b5-38397d7f3ac7" xlink:to="loc_srt_RangeAxis_4d84557c-2e66-4d29-9eba-634283a920b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4d84557c-2e66-4d29-9eba-634283a920b5_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_4d84557c-2e66-4d29-9eba-634283a920b5" xlink:to="loc_srt_RangeMember_4d84557c-2e66-4d29-9eba-634283a920b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6aa3909b-d94f-49ec-8abb-2917e545a4d4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_4d84557c-2e66-4d29-9eba-634283a920b5" xlink:to="loc_srt_RangeMember_6aa3909b-d94f-49ec-8abb-2917e545a4d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_067f51e4-c5ac-469b-92e2-38a37ae50b7b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_6aa3909b-d94f-49ec-8abb-2917e545a4d4" xlink:to="loc_srt_MinimumMember_067f51e4-c5ac-469b-92e2-38a37ae50b7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_f2b99f24-1b89-42cd-a4ea-fe8349f83ad6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_6aa3909b-d94f-49ec-8abb-2917e545a4d4" xlink:to="loc_srt_MaximumMember_f2b99f24-1b89-42cd-a4ea-fe8349f83ad6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveCurrent_cd99f48c-000a-40af-8d44-d7f30a9f0f14" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserveCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_954cfb69-2de4-4180-a001-c84072ba1df1" xlink:to="loc_us-gaap_RestructuringReserveCurrent_cd99f48c-000a-40af-8d44-d7f30a9f0f14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveNoncurrent_e6e8dd06-61fd-4c36-98a6-1b81b908312c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserveNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_954cfb69-2de4-4180-a001-c84072ba1df1" xlink:to="loc_us-gaap_RestructuringReserveNoncurrent_e6e8dd06-61fd-4c36-98a6-1b81b908312c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/RestructuringRelatedBalanceSheetActivityDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#RestructuringRelatedBalanceSheetActivityDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/RestructuringRelatedBalanceSheetActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_4148ce3e-c65d-41e1-adcb-faf4a27bfaf5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_4148ce3e-c65d-41e1-adcb-faf4a27bfaf5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_239c5416-24b8-443e-b7dd-304fac3acd4b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_4148ce3e-c65d-41e1-adcb-faf4a27bfaf5" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_239c5416-24b8-443e-b7dd-304fac3acd4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_239c5416-24b8-443e-b7dd-304fac3acd4b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_239c5416-24b8-443e-b7dd-304fac3acd4b" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_239c5416-24b8-443e-b7dd-304fac3acd4b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_b2416a37-7aa5-4f01-994a-9f7575bf659a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_239c5416-24b8-443e-b7dd-304fac3acd4b" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_b2416a37-7aa5-4f01-994a-9f7575bf659a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_499aa249-55fb-479a-8950-b661bc16c05e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_b2416a37-7aa5-4f01-994a-9f7575bf659a" xlink:to="loc_us-gaap_EmployeeSeveranceMember_499aa249-55fb-479a-8950-b661bc16c05e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember_7864d06f-0058-41a0-a6e2-77bd1eb23c1a" xlink:href="itri-20240930.xsd#itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_b2416a37-7aa5-4f01-994a-9f7575bf659a" xlink:to="loc_itri_AssetImpairmentAndNetGainLossOnSaleOrDisposalMember_7864d06f-0058-41a0-a6e2-77bd1eb23c1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRestructuringMember_5539c217-ca09-4546-ac91-fb717ea0ce56" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherRestructuringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_b2416a37-7aa5-4f01-994a-9f7575bf659a" xlink:to="loc_us-gaap_OtherRestructuringMember_5539c217-ca09-4546-ac91-fb717ea0ce56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_a974c294-5cfa-4bf6-b1c3-a50c95e92623" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_RestructuringReserve_a974c294-5cfa-4bf6-b1c3-a50c95e92623" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_4ba9c672-3c16-48b1-a39a-a92cc3687088" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_RestructuringCharges_4ba9c672-3c16-48b1-a39a-a92cc3687088" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_704ee49f-b2e7-4b93-a0f3-ac73f7dc3b62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_PaymentsForRestructuring_704ee49f-b2e7-4b93-a0f3-ac73f7dc3b62" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_8b9e5428-a8f0-480c-867e-45acf9ede762" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostsAndAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_8b9e5428-a8f0-480c-867e-45acf9ede762" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveTranslationAdjustment_87d89f1c-fa3e-43ea-8285-7f986ee1d28d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserveTranslationAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_ed7cbf46-beab-49a5-8a35-b1365802605c" xlink:to="loc_us-gaap_RestructuringReserveTranslationAdjustment_87d89f1c-fa3e-43ea-8285-7f986ee1d28d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_ae7957a2-bb21-4536-af0c-ffd8f2d870a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserve"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/ShareholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#ShareholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareRepurchaseProgramAxis_61b67685-1b7b-4632-8ce1-45b5d1ade1c6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:to="loc_us-gaap_ShareRepurchaseProgramAxis_61b67685-1b7b-4632-8ce1-45b5d1ade1c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_61b67685-1b7b-4632-8ce1-45b5d1ade1c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_61b67685-1b7b-4632-8ce1-45b5d1ade1c6" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_61b67685-1b7b-4632-8ce1-45b5d1ade1c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_30390da6-e320-484c-af9b-fddc19e0dc3e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_61b67685-1b7b-4632-8ce1-45b5d1ade1c6" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_30390da6-e320-484c-af9b-fddc19e0dc3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2024StockRepurchaseProgramMember_cf1fc541-86ee-4c12-b62a-b57674a0fedb" xlink:href="itri-20240930.xsd#itri_A2024StockRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_30390da6-e320-484c-af9b-fddc19e0dc3e" xlink:to="loc_itri_A2024StockRepurchaseProgramMember_cf1fc541-86ee-4c12-b62a-b57674a0fedb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2023StockRepurchaseProgramMember_b4e02b03-d26a-4089-93ec-06e4ab302e3d" xlink:href="itri-20240930.xsd#itri_A2023StockRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_30390da6-e320-484c-af9b-fddc19e0dc3e" xlink:to="loc_itri_A2023StockRepurchaseProgramMember_b4e02b03-d26a-4089-93ec-06e4ab302e3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_ff21a862-eb81-42e9-a839-210c86dd22aa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_ff21a862-eb81-42e9-a839-210c86dd22aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_ff21a862-eb81-42e9-a839-210c86dd22aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_ff21a862-eb81-42e9-a839-210c86dd22aa" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_ff21a862-eb81-42e9-a839-210c86dd22aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_c8a47b8a-3f60-4850-aa43-b3db6904e761" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_ff21a862-eb81-42e9-a839-210c86dd22aa" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_c8a47b8a-3f60-4850-aa43-b3db6904e761" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_2f0677e6-4e16-420f-8181-dd78908380b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_c8a47b8a-3f60-4850-aa43-b3db6904e761" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_2f0677e6-4e16-420f-8181-dd78908380b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_d0cc1029-9c97-4ad3-ad23-e063142a6c89" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:to="loc_us-gaap_DebtInstrumentAxis_d0cc1029-9c97-4ad3-ad23-e063142a6c89" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_d0cc1029-9c97-4ad3-ad23-e063142a6c89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_d0cc1029-9c97-4ad3-ad23-e063142a6c89" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_d0cc1029-9c97-4ad3-ad23-e063142a6c89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_55c8019c-a6ba-4321-9228-823cc22cc838" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_d0cc1029-9c97-4ad3-ad23-e063142a6c89" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_55c8019c-a6ba-4321-9228-823cc22cc838" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_A2024NotesMember_49bf0152-3784-453e-a3a7-965715ba534c" xlink:href="itri-20240930.xsd#itri_A2024NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_55c8019c-a6ba-4321-9228-823cc22cc838" xlink:to="loc_itri_A2024NotesMember_49bf0152-3784-453e-a3a7-965715ba534c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_be51e083-b41e-4db4-ac4c-4ef55ef802df" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityEquityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_80dd9950-de17-403b-9b0e-876591e75960" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_be51e083-b41e-4db4-ac4c-4ef55ef802df" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_be51e083-b41e-4db4-ac4c-4ef55ef802df_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_be51e083-b41e-4db4-ac4c-4ef55ef802df" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_be51e083-b41e-4db4-ac4c-4ef55ef802df_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a559adce-d11d-43a6-82de-e338125c4b46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityEquityAxis_be51e083-b41e-4db4-ac4c-4ef55ef802df" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a559adce-d11d-43a6-82de-e338125c4b46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CallOptionMember_f4527d75-5b60-4a60-8021-158db6ef939b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CallOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a559adce-d11d-43a6-82de-e338125c4b46" xlink:to="loc_us-gaap_CallOptionMember_f4527d75-5b60-4a60-8021-158db6ef939b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_0cf16ace-6c88-414d-a28e-20cc891b99e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_0cf16ace-6c88-414d-a28e-20cc891b99e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockNoParValue_5f6b0dbc-38ce-4ff9-9c7d-fe38a0bea055" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockNoParValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_PreferredStockNoParValue_5f6b0dbc-38ce-4ff9-9c7d-fe38a0bea055" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_8b775bdb-1181-4180-bc76-c77ea061dfab" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_8b775bdb-1181-4180-bc76-c77ea061dfab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_75cd5790-7bf0-4383-b7fc-ce8f510debeb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_PreferredStockSharesIssued_75cd5790-7bf0-4383-b7fc-ce8f510debeb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_b3c1bb6a-3284-4b94-8a82-9d6b9cdd33e3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_b3c1bb6a-3284-4b94-8a82-9d6b9cdd33e3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_34c2d617-6a41-46e4-9484-e8c79d8f9856" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_34c2d617-6a41-46e4-9484-e8c79d8f9856" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_9e7d55cf-6a87-488c-bc98-04b46bffd93b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_9e7d55cf-6a87-488c-bc98-04b46bffd93b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_c174ee35-5e64-4e3a-ba69-9b130d96b9b9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_c174ee35-5e64-4e3a-ba69-9b130d96b9b9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_e224ef3c-70ec-45f7-b79c-530e2989038e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_DerivativeNotionalAmount_e224ef3c-70ec-45f7-b79c-530e2989038e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6a7f7528-d799-447d-86f1-42b6f95bf4e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6a7f7528-d799-447d-86f1-42b6f95bf4e1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_CommonStockConversionPrice_8fdf6650-ee99-4e41-8793-dd17119d22ee" xlink:href="itri-20240930.xsd#itri_CommonStockConversionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_itri_CommonStockConversionPrice_8fdf6650-ee99-4e41-8793-dd17119d22ee" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsDerivativeInstruments_632df37e-0bc7-4493-8142-137a854e5223" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxAssetsDerivativeInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_DeferredTaxAssetsDerivativeInstruments_632df37e-0bc7-4493-8142-137a854e5223" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_713e1b0b-dbcc-4e28-932d-f82f02b19e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_713e1b0b-dbcc-4e28-932d-f82f02b19e7d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_129f924f-64d9-4b72-a815-1a0ee637bae4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_129f924f-64d9-4b72-a815-1a0ee637bae4" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_ClassOfWarrantOrRightPremiumPercentage_d2e45212-2e77-4141-98b6-b28a61727d31" xlink:href="itri-20240930.xsd#itri_ClassOfWarrantOrRightPremiumPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_itri_ClassOfWarrantOrRightPremiumPercentage_d2e45212-2e77-4141-98b6-b28a61727d31" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_ClassOfWarrantOrRightAggregateProceedsFromTransaction_3227b922-b119-464b-827d-62cbeff157c6" xlink:href="itri-20240930.xsd#itri_ClassOfWarrantOrRightAggregateProceedsFromTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_itri_ClassOfWarrantOrRightAggregateProceedsFromTransaction_3227b922-b119-464b-827d-62cbeff157c6" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityShares_d3bd50b8-bdc3-4af0-8feb-74351b0fa0a5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityShares_d3bd50b8-bdc3-4af0-8feb-74351b0fa0a5" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_b1ff2160-f634-40ee-942a-ebdc9674538c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OptionIndexedToIssuersEquityStrikePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityStrikePrice1_b1ff2160-f634-40ee-942a-ebdc9674538c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OptionIndexedToIssuersEquityCapPrice_cedbac1e-2837-448e-a5b8-408c699e03e8" xlink:href="itri-20240930.xsd#itri_OptionIndexedToIssuersEquityCapPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_itri_OptionIndexedToIssuersEquityCapPrice_cedbac1e-2837-448e-a5b8-408c699e03e8" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsEquityMethodInvestments_4b0fb793-5972-42ff-bbda-8e2cd0da6562" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxAssetsEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_83bfd452-5a95-4bfa-8e35-14fa6d32d5ff" xlink:to="loc_us-gaap_DeferredTaxAssetsEquityMethodInvestments_4b0fb793-5972-42ff-bbda-8e2cd0da6562" xlink:type="arc" order="19"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/ShareholdersEquityAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#ShareholdersEquityAccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ShareholdersEquityAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_db207803-5db7-4e0b-b242-3012e95349d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1ba6e388-cd8c-4138-b1bf-adde7d9145e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_db207803-5db7-4e0b-b242-3012e95349d8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1ba6e388-cd8c-4138-b1bf-adde7d9145e0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_ead97054-fe80-44f3-a0fd-f059c192ac7f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1ba6e388-cd8c-4138-b1bf-adde7d9145e0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_ead97054-fe80-44f3-a0fd-f059c192ac7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ead97054-fe80-44f3-a0fd-f059c192ac7f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ead97054-fe80-44f3-a0fd-f059c192ac7f" xlink:to="loc_us-gaap_EquityComponentDomain_ead97054-fe80-44f3-a0fd-f059c192ac7f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_51bf49c8-4f5a-47e5-86c7-fac06769c357" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ead97054-fe80-44f3-a0fd-f059c192ac7f" xlink:to="loc_us-gaap_EquityComponentDomain_51bf49c8-4f5a-47e5-86c7-fac06769c357" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_51bf49c8-4f5a-47e5-86c7-fac06769c357" xlink:to="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_c9b47773-9118-4c81-94ed-5493b886857a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_c9b47773-9118-4c81-94ed-5493b886857a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_a0d20d12-32f3-4f7f-b8fb-3cdd1ffd1c30" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:to="loc_us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_a0d20d12-32f3-4f7f-b8fb-3cdd1ffd1c30" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_AccumulatedOtherComprehensiveIncomeNetUnrealizedGainLossOnNonderivativeInstrumentsMember_f63f0bf4-c06e-43d8-ba0f-5d92ca12c090" xlink:href="itri-20240930.xsd#itri_AccumulatedOtherComprehensiveIncomeNetUnrealizedGainLossOnNonderivativeInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:to="loc_itri_AccumulatedOtherComprehensiveIncomeNetUnrealizedGainLossOnNonderivativeInstrumentsMember_f63f0bf4-c06e-43d8-ba0f-5d92ca12c090" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_54e7fd24-5bd2-4641-8701-f08d50bbf345" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_54e7fd24-5bd2-4641-8701-f08d50bbf345" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_9bb9147d-af3b-4941-8008-421b5fc3777f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_f8b14e15-8d9f-44a5-8802-bc9fea83d947" xlink:to="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_9bb9147d-af3b-4941-8008-421b5fc3777f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_db207803-5db7-4e0b-b242-3012e95349d8" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d46774b-c956-45d4-ba28-9458e28dce16" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d46774b-c956-45d4-ba28-9458e28dce16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_d4ea5f2b-e1ba-456b-9df1-1ad45cff17c1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_d4ea5f2b-e1ba-456b-9df1-1ad45cff17c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_e1f0719d-05d6-4844-b3d7-249e159ce8bb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_e1f0719d-05d6-4844-b3d7-249e159ce8bb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_bba90cdb-8c4c-49e4-9a73-09ca524226cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_5967f0c6-a9c5-4cc5-92c2-4fe8ad679fb2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_bba90cdb-8c4c-49e4-9a73-09ca524226cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_68ca1632-ca78-4390-a344-9402948c94be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/ScheduleofFairValuesofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#ScheduleofFairValuesofFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/ScheduleofFairValuesofFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_67b9d05b-7794-4378-a738-70b83c18a70d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0987d900-c03f-4534-992b-adbb7b57c199" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_67b9d05b-7794-4378-a738-70b83c18a70d" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0987d900-c03f-4534-992b-adbb7b57c199" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_856aa1b0-4d93-47d2-be1a-f12e9fc415f7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0987d900-c03f-4534-992b-adbb7b57c199" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_856aa1b0-4d93-47d2-be1a-f12e9fc415f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_856aa1b0-4d93-47d2-be1a-f12e9fc415f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_856aa1b0-4d93-47d2-be1a-f12e9fc415f7" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_856aa1b0-4d93-47d2-be1a-f12e9fc415f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2efba491-215a-4fdd-be5e-026d2532b50c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_856aa1b0-4d93-47d2-be1a-f12e9fc415f7" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2efba491-215a-4fdd-be5e-026d2532b50c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_305dff35-963e-43d0-8dd8-11eb066ebe62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2efba491-215a-4fdd-be5e-026d2532b50c" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_305dff35-963e-43d0-8dd8-11eb066ebe62" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_e59503ac-ac35-4518-b6d0-d8c0894f99f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_305dff35-963e-43d0-8dd8-11eb066ebe62" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_e59503ac-ac35-4518-b6d0-d8c0894f99f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_0b736a49-f1dc-4628-b5f0-337410b5f9e0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_305dff35-963e-43d0-8dd8-11eb066ebe62" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_0b736a49-f1dc-4628-b5f0-337410b5f9e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_4ab74996-e87f-45bb-92ec-b6a691b68814" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_0987d900-c03f-4534-992b-adbb7b57c199" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_4ab74996-e87f-45bb-92ec-b6a691b68814" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_4ab74996-e87f-45bb-92ec-b6a691b68814_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4ab74996-e87f-45bb-92ec-b6a691b68814" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_4ab74996-e87f-45bb-92ec-b6a691b68814_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ffded130-b66a-45a1-8e80-f09fc0d036de" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_4ab74996-e87f-45bb-92ec-b6a691b68814" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ffded130-b66a-45a1-8e80-f09fc0d036de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_UsdDenominatedTermLoanMember_b30ebb37-d1a5-4c55-a931-a136077bc27e" xlink:href="itri-20240930.xsd#itri_UsdDenominatedTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ffded130-b66a-45a1-8e80-f09fc0d036de" xlink:to="loc_itri_UsdDenominatedTermLoanMember_b30ebb37-d1a5-4c55-a931-a136077bc27e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_37e2185d-779b-4a40-9268-a4d716fed37f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ffded130-b66a-45a1-8e80-f09fc0d036de" xlink:to="loc_us-gaap_LineOfCreditMember_37e2185d-779b-4a40-9268-a4d716fed37f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_45a32e30-d0a7-4bb3-a89c-c62090fea68b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_67b9d05b-7794-4378-a738-70b83c18a70d" xlink:to="loc_us-gaap_LiabilitiesAbstract_45a32e30-d0a7-4bb3-a89c-c62090fea68b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_048d3688-a205-438c-9a67-d447e276b520" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_45a32e30-d0a7-4bb3-a89c-c62090fea68b" xlink:to="loc_us-gaap_LineOfCredit_048d3688-a205-438c-9a67-d447e276b520" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_a9ed5ec6-8d46-4008-9d73-9b9396ea8d57" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_45a32e30-d0a7-4bb3-a89c-c62090fea68b" xlink:to="loc_us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_a9ed5ec6-8d46-4008-9d73-9b9396ea8d57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleNotesPayable_aea96d81-e620-43a3-b672-175cc0aead1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertibleNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_45a32e30-d0a7-4bb3-a89c-c62090fea68b" xlink:to="loc_us-gaap_ConvertibleNotesPayable_aea96d81-e620-43a3-b672-175cc0aead1d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/SegmentInformationNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#SegmentInformationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/SegmentInformationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_8d0613c6-d0cf-4946-a47e-56a6fa460c8c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_7e6a06fb-ac1b-4625-8f21-a930e5b9ff23" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_8d0613c6-d0cf-4946-a47e-56a6fa460c8c" xlink:to="loc_us-gaap_ConcentrationRiskTable_7e6a06fb-ac1b-4625-8f21-a930e5b9ff23" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_a685e0ff-1930-4e3f-8136-03ecaa2ada1a" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_7e6a06fb-ac1b-4625-8f21-a930e5b9ff23" xlink:to="loc_srt_MajorCustomersAxis_a685e0ff-1930-4e3f-8136-03ecaa2ada1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_a685e0ff-1930-4e3f-8136-03ecaa2ada1a_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_a685e0ff-1930-4e3f-8136-03ecaa2ada1a" xlink:to="loc_srt_NameOfMajorCustomerDomain_a685e0ff-1930-4e3f-8136-03ecaa2ada1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_d43f0c38-9d38-4d0a-b7a4-1585ab2b65e6" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_a685e0ff-1930-4e3f-8136-03ecaa2ada1a" xlink:to="loc_srt_NameOfMajorCustomerDomain_d43f0c38-9d38-4d0a-b7a4-1585ab2b65e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OneCustomerMember_5b5f9992-1bd7-43c5-b636-910e4e416abd" xlink:href="itri-20240930.xsd#itri_OneCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_d43f0c38-9d38-4d0a-b7a4-1585ab2b65e6" xlink:to="loc_itri_OneCustomerMember_5b5f9992-1bd7-43c5-b636-910e4e416abd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_33e21c7e-ab1a-4a53-8eb4-276de005bae5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_7e6a06fb-ac1b-4625-8f21-a930e5b9ff23" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_33e21c7e-ab1a-4a53-8eb4-276de005bae5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_33e21c7e-ab1a-4a53-8eb4-276de005bae5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_33e21c7e-ab1a-4a53-8eb4-276de005bae5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_33e21c7e-ab1a-4a53-8eb4-276de005bae5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_53cffe95-cbe1-4ba6-8efd-0430e8da3dae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_33e21c7e-ab1a-4a53-8eb4-276de005bae5" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_53cffe95-cbe1-4ba6-8efd-0430e8da3dae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_91dd4f6b-593c-4af8-b7e7-a468121f1a22" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_53cffe95-cbe1-4ba6-8efd-0430e8da3dae" xlink:to="loc_us-gaap_SalesRevenueNetMember_91dd4f6b-593c-4af8-b7e7-a468121f1a22" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_7e6a06fb-ac1b-4625-8f21-a930e5b9ff23" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_fc0d9561-f77e-42f0-ba29-da6a3e62a731" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3540e957-3fe2-40e6-b8a4-9d70b9b7a85f" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_fc0d9561-f77e-42f0-ba29-da6a3e62a731" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_acb2999e-ca23-4487-af8d-e797d09a3263" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_fc0d9561-f77e-42f0-ba29-da6a3e62a731" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_acb2999e-ca23-4487-af8d-e797d09a3263" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_1e508eeb-7e9a-4a39-b492-d2edbaeecad2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_8d0613c6-d0cf-4946-a47e-56a6fa460c8c" xlink:to="loc_us-gaap_NumberOfReportableSegments_1e508eeb-7e9a-4a39-b492-d2edbaeecad2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_99979a20-55d0-4995-b082-fffa0d6520f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_8d0613c6-d0cf-4946-a47e-56a6fa460c8c" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_99979a20-55d0-4995-b082-fffa0d6520f2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/InformationBySegmentDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#InformationBySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/InformationBySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6ebbffe7-39ef-4188-9a43-0145d805a0d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6ebbffe7-39ef-4188-9a43-0145d805a0d1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_c0ff6c5c-24c2-4546-a578-f119e0a60ad0" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6ebbffe7-39ef-4188-9a43-0145d805a0d1" xlink:to="loc_srt_ProductOrServiceAxis_c0ff6c5c-24c2-4546-a578-f119e0a60ad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_c0ff6c5c-24c2-4546-a578-f119e0a60ad0_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_c0ff6c5c-24c2-4546-a578-f119e0a60ad0" xlink:to="loc_srt_ProductsAndServicesDomain_c0ff6c5c-24c2-4546-a578-f119e0a60ad0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_7fc33da7-a0be-4b13-b5bb-9feb63e1217f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_c0ff6c5c-24c2-4546-a578-f119e0a60ad0" xlink:to="loc_srt_ProductsAndServicesDomain_7fc33da7-a0be-4b13-b5bb-9feb63e1217f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_377b773f-a1bb-48d6-83ac-d91482f6713c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_7fc33da7-a0be-4b13-b5bb-9feb63e1217f" xlink:to="loc_us-gaap_ProductMember_377b773f-a1bb-48d6-83ac-d91482f6713c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_0ed04756-d9ac-433e-ab4d-8e3996b919c4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_7fc33da7-a0be-4b13-b5bb-9feb63e1217f" xlink:to="loc_us-gaap_ServiceMember_0ed04756-d9ac-433e-ab4d-8e3996b919c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_05bdd739-d601-42fa-8a78-9f6bc9d7edf9" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6ebbffe7-39ef-4188-9a43-0145d805a0d1" xlink:to="loc_srt_ConsolidationItemsAxis_05bdd739-d601-42fa-8a78-9f6bc9d7edf9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_05bdd739-d601-42fa-8a78-9f6bc9d7edf9_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_05bdd739-d601-42fa-8a78-9f6bc9d7edf9" xlink:to="loc_srt_ConsolidationItemsDomain_05bdd739-d601-42fa-8a78-9f6bc9d7edf9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_9e8ea8dd-77e7-4df2-9cfb-a5c95a60868b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_05bdd739-d601-42fa-8a78-9f6bc9d7edf9" xlink:to="loc_srt_ConsolidationItemsDomain_9e8ea8dd-77e7-4df2-9cfb-a5c95a60868b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_504ec851-1a33-4e06-9100-87d9448ecc72" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9e8ea8dd-77e7-4df2-9cfb-a5c95a60868b" xlink:to="loc_us-gaap_OperatingSegmentsMember_504ec851-1a33-4e06-9100-87d9448ecc72" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_474af348-f505-4e77-8f05-09318edcdb43" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9e8ea8dd-77e7-4df2-9cfb-a5c95a60868b" xlink:to="loc_us-gaap_CorporateNonSegmentMember_474af348-f505-4e77-8f05-09318edcdb43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_597a2704-a2f5-47f4-8245-648cc420d428" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6ebbffe7-39ef-4188-9a43-0145d805a0d1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_597a2704-a2f5-47f4-8245-648cc420d428" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_597a2704-a2f5-47f4-8245-648cc420d428_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_597a2704-a2f5-47f4-8245-648cc420d428" xlink:to="loc_us-gaap_SegmentDomain_597a2704-a2f5-47f4-8245-648cc420d428_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c4ced99b-65cd-4b81-9b6e-d53de3284f49" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_597a2704-a2f5-47f4-8245-648cc420d428" xlink:to="loc_us-gaap_SegmentDomain_c4ced99b-65cd-4b81-9b6e-d53de3284f49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_DeviceSolutionsMember_62313853-d20c-4342-b72b-5545ca09a79e" xlink:href="itri-20240930.xsd#itri_DeviceSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c4ced99b-65cd-4b81-9b6e-d53de3284f49" xlink:to="loc_itri_DeviceSolutionsMember_62313853-d20c-4342-b72b-5545ca09a79e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_NetworkedSolutionsSegmentMember_a7ee4aa6-8f56-4bdb-8c4f-e71eba4d8d5a" xlink:href="itri-20240930.xsd#itri_NetworkedSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c4ced99b-65cd-4b81-9b6e-d53de3284f49" xlink:to="loc_itri_NetworkedSolutionsSegmentMember_a7ee4aa6-8f56-4bdb-8c4f-e71eba4d8d5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OutcomesSegmentMember_ae24754f-10f9-46a7-a4ba-4f3d90fa247d" xlink:href="itri-20240930.xsd#itri_OutcomesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c4ced99b-65cd-4b81-9b6e-d53de3284f49" xlink:to="loc_itri_OutcomesSegmentMember_ae24754f-10f9-46a7-a4ba-4f3d90fa247d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_276db45c-8f39-4948-a9d4-57035bca7a41" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_276db45c-8f39-4948-a9d4-57035bca7a41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_ab2d0204-8fe2-4f38-8d62-1e60fa6e97d7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_GrossProfit_ab2d0204-8fe2-4f38-8d62-1e60fa6e97d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_314794a2-9bb7-4b37-a5b6-bd1eb22cac04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_OperatingIncomeLoss_314794a2-9bb7-4b37-a5b6-bd1eb22cac04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_64ee583b-21c3-4f08-b0cc-6a5c3f4920af" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_64ee583b-21c3-4f08-b0cc-6a5c3f4920af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_eac0c73b-c171-46ab-a20a-56e40c2316a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_5c91ec05-ae6a-4408-a169-7f9a1fb2aa2c" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_eac0c73b-c171-46ab-a20a-56e40c2316a9" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/SegmentInformationRevenuesByRegionDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#SegmentInformationRevenuesByRegionDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/SegmentInformationRevenuesByRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f6fb9bce-04da-4f45-bddc-038d1572f298" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_3b7047fa-53e2-4f27-8e74-f127102476d2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f6fb9bce-04da-4f45-bddc-038d1572f298" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_3b7047fa-53e2-4f27-8e74-f127102476d2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_b9c05485-baf6-4f71-9175-5917664b19c7" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_3b7047fa-53e2-4f27-8e74-f127102476d2" xlink:to="loc_srt_StatementGeographicalAxis_b9c05485-baf6-4f71-9175-5917664b19c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b9c05485-baf6-4f71-9175-5917664b19c7_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_b9c05485-baf6-4f71-9175-5917664b19c7" xlink:to="loc_srt_SegmentGeographicalDomain_b9c05485-baf6-4f71-9175-5917664b19c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_1333799b-cb91-4647-a232-515b9e005117" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_b9c05485-baf6-4f71-9175-5917664b19c7" xlink:to="loc_srt_SegmentGeographicalDomain_1333799b-cb91-4647-a232-515b9e005117" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_UnitedStatesAndCanadaMember_e343ddf8-7cd7-4ed3-9e43-c72f926fd341" xlink:href="itri-20240930.xsd#itri_UnitedStatesAndCanadaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1333799b-cb91-4647-a232-515b9e005117" xlink:to="loc_itri_UnitedStatesAndCanadaMember_e343ddf8-7cd7-4ed3-9e43-c72f926fd341" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_d7c3a2a7-4f7e-4610-9c30-4fba6df1c1e6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1333799b-cb91-4647-a232-515b9e005117" xlink:to="loc_us-gaap_EMEAMember_d7c3a2a7-4f7e-4610-9c30-4fba6df1c1e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_b9a5fd79-015e-431b-8053-2e3e64ee297e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1333799b-cb91-4647-a232-515b9e005117" xlink:to="loc_srt_AsiaPacificMember_b9a5fd79-015e-431b-8053-2e3e64ee297e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_40e1e102-1414-4259-b9cb-cc14acc4f935" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f6fb9bce-04da-4f45-bddc-038d1572f298" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_40e1e102-1414-4259-b9cb-cc14acc4f935" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/DepreciationandAmortizationbySegmentDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#DepreciationandAmortizationbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/DepreciationandAmortizationbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_d6167c96-5e62-41b9-9b14-6e2ff1a3253e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_91d90296-c4ff-4d2f-abb4-2c71309435b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_d6167c96-5e62-41b9-9b14-6e2ff1a3253e" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_91d90296-c4ff-4d2f-abb4-2c71309435b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_1452e6d6-2d9f-4954-92e8-c342d72cbbc8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_91d90296-c4ff-4d2f-abb4-2c71309435b3" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_1452e6d6-2d9f-4954-92e8-c342d72cbbc8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_1452e6d6-2d9f-4954-92e8-c342d72cbbc8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1452e6d6-2d9f-4954-92e8-c342d72cbbc8" xlink:to="loc_us-gaap_SegmentDomain_1452e6d6-2d9f-4954-92e8-c342d72cbbc8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_288e6fae-53e7-4cbb-ad7c-98bd65de93d5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_1452e6d6-2d9f-4954-92e8-c342d72cbbc8" xlink:to="loc_us-gaap_SegmentDomain_288e6fae-53e7-4cbb-ad7c-98bd65de93d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_DeviceSolutionsMember_3b72663e-ee69-4e82-a284-241fe25710b2" xlink:href="itri-20240930.xsd#itri_DeviceSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_288e6fae-53e7-4cbb-ad7c-98bd65de93d5" xlink:to="loc_itri_DeviceSolutionsMember_3b72663e-ee69-4e82-a284-241fe25710b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_NetworkedSolutionsSegmentMember_48696675-52d4-468e-aba0-a20e6cb417cc" xlink:href="itri-20240930.xsd#itri_NetworkedSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_288e6fae-53e7-4cbb-ad7c-98bd65de93d5" xlink:to="loc_itri_NetworkedSolutionsSegmentMember_48696675-52d4-468e-aba0-a20e6cb417cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_OutcomesSegmentMember_2d91900c-d2b6-461e-b97b-ed06fc33539c" xlink:href="itri-20240930.xsd#itri_OutcomesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_288e6fae-53e7-4cbb-ad7c-98bd65de93d5" xlink:to="loc_itri_OutcomesSegmentMember_2d91900c-d2b6-461e-b97b-ed06fc33539c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_34e9c7f6-5565-4af4-b40f-5d664d71028e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_91d90296-c4ff-4d2f-abb4-2c71309435b3" xlink:to="loc_srt_ConsolidationItemsAxis_34e9c7f6-5565-4af4-b40f-5d664d71028e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_34e9c7f6-5565-4af4-b40f-5d664d71028e_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_34e9c7f6-5565-4af4-b40f-5d664d71028e" xlink:to="loc_srt_ConsolidationItemsDomain_34e9c7f6-5565-4af4-b40f-5d664d71028e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_e44e8e22-803a-4b1e-a51e-48ec11763189" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_34e9c7f6-5565-4af4-b40f-5d664d71028e" xlink:to="loc_srt_ConsolidationItemsDomain_e44e8e22-803a-4b1e-a51e-48ec11763189" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_6f5fddea-f772-47f9-86f6-86549aeccd9a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e44e8e22-803a-4b1e-a51e-48ec11763189" xlink:to="loc_us-gaap_CorporateNonSegmentMember_6f5fddea-f772-47f9-86f6-86549aeccd9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_a0a9743e-de64-4127-8903-10052f0b7623" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e44e8e22-803a-4b1e-a51e-48ec11763189" xlink:to="loc_us-gaap_OperatingSegmentsMember_a0a9743e-de64-4127-8903-10052f0b7623" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_b181da21-8703-4883-9613-268a58a42b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_d6167c96-5e62-41b9-9b14-6e2ff1a3253e" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_b181da21-8703-4883-9613-268a58a42b4a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/RevenueRecognitionRemainingPerformanceObligationDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#RevenueRecognitionRemainingPerformanceObligationDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/RevenueRecognitionRemainingPerformanceObligationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_072169d3-9b75-46da-ac5b-bb87bf50c7f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_072169d3-9b75-46da-ac5b-bb87bf50c7f2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_686cdc76-2dda-4f8f-bdac-0556fbea769a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_072169d3-9b75-46da-ac5b-bb87bf50c7f2" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_686cdc76-2dda-4f8f-bdac-0556fbea769a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_2004ad90-6dfa-48f3-8b20-ed27cb67778f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_2004ad90-6dfa-48f3-8b20-ed27cb67778f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_eb9dad4a-2bbf-4c55-936c-30e4862e929a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_eb9dad4a-2bbf-4c55-936c-30e4862e929a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/RevenueRecognitionRemainingPerformanceObligationDetails_1" xlink:type="simple" xlink:href="itri-20240930.xsd#RevenueRecognitionRemainingPerformanceObligationDetails_1"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/RevenueRecognitionRemainingPerformanceObligationDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_072169d3-9b75-46da-ac5b-bb87bf50c7f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_072169d3-9b75-46da-ac5b-bb87bf50c7f2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_2004ad90-6dfa-48f3-8b20-ed27cb67778f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_2004ad90-6dfa-48f3-8b20-ed27cb67778f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_eb9dad4a-2bbf-4c55-936c-30e4862e929a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_781b4cc2-292b-46e6-8921-090d89929c77" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_eb9dad4a-2bbf-4c55-936c-30e4862e929a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.itron.com/role/BusinessCombinationsNarrativeDetails" xlink:type="simple" xlink:href="itri-20240930.xsd#BusinessCombinationsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.itron.com/role/BusinessCombinationsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_49db9229-4aab-4d44-a876-3fc3c1df31e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_26217072-37a7-4cf2-ab91-79e45babd6fd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_49db9229-4aab-4d44-a876-3fc3c1df31e1" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_26217072-37a7-4cf2-ab91-79e45babd6fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_8fd78c01-3aa4-45ac-9d15-002426f24bb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_26217072-37a7-4cf2-ab91-79e45babd6fd" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_8fd78c01-3aa4-45ac-9d15-002426f24bb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8fd78c01-3aa4-45ac-9d15-002426f24bb9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8fd78c01-3aa4-45ac-9d15-002426f24bb9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8fd78c01-3aa4-45ac-9d15-002426f24bb9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_35e2ac53-b3ba-473a-8216-3086b690173d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8fd78c01-3aa4-45ac-9d15-002426f24bb9" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_35e2ac53-b3ba-473a-8216-3086b690173d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_itri_ElpisSquaredMember_b5eaf555-3ac4-4f30-ae69-21e78532555f" xlink:href="itri-20240930.xsd#itri_ElpisSquaredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_35e2ac53-b3ba-473a-8216-3086b690173d" xlink:to="loc_itri_ElpisSquaredMember_b5eaf555-3ac4-4f30-ae69-21e78532555f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_05f60016-37e4-4b31-a641-d4ae00b5ea75" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_49db9229-4aab-4d44-a876-3fc3c1df31e1" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_05f60016-37e4-4b31-a641-d4ae00b5ea75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_b72c4e50-88f3-472e-bb57-c912f2b39482" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_49db9229-4aab-4d44-a876-3fc3c1df31e1" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_b72c4e50-88f3-472e-bb57-c912f2b39482" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_c9a84d71-00fe-46a0-8e75-5cdd67997175" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_49db9229-4aab-4d44-a876-3fc3c1df31e1" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_c9a84d71-00fe-46a0-8e75-5cdd67997175" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
