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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019fb94e-da31-77e5-acbf-42e819ed3b45,g:c61d10ef-bcb7-45a6-b463-019eba80bdac-->
<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.xyleminc.com/role/ConsolidatedIncomeStatements" xlink:type="simple" xlink:href="xyl-20260930.xsd#ConsolidatedIncomeStatements"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ConsolidatedIncomeStatements" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019fb94e-dcd8-7e4b-837e-95de4fad96e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_StatementTable_019fb94e-dcd8-7e4b-837e-95de4fad96e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019fb94e-dcd8-748f-9ac3-04dbad192f4e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019fb94e-dcd8-7e4b-837e-95de4fad96e9" xlink:to="loc_srt_ProductOrServiceAxis_019fb94e-dcd8-748f-9ac3-04dbad192f4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-748f-9ac3-04dbad192f4e_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019fb94e-dcd8-748f-9ac3-04dbad192f4e" xlink:to="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-748f-9ac3-04dbad192f4e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-7b2e-bafc-67d345a18cd3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019fb94e-dcd8-748f-9ac3-04dbad192f4e" xlink:to="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-7b2e-bafc-67d345a18cd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019fb94e-dcd8-7c40-9327-5fa77fbe6481" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-7b2e-bafc-67d345a18cd3" xlink:to="loc_us-gaap_ProductMember_019fb94e-dcd8-7c40-9327-5fa77fbe6481" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019fb94e-dcd8-7bb5-b1b5-d2cfe0655ddd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dcd8-7b2e-bafc-67d345a18cd3" xlink:to="loc_us-gaap_ServiceMember_019fb94e-dcd8-7bb5-b1b5-d2cfe0655ddd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fb94e-dcd8-7c0a-ad56-5cc2e27adbba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fb94e-dcd8-7c0a-ad56-5cc2e27adbba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019fb94e-dcd8-75ab-b104-fd8e649eb8c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_CostOfRevenue_019fb94e-dcd8-75ab-b104-fd8e649eb8c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019fb94e-dcd8-7744-8222-ec76afe04ccd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_GrossProfit_019fb94e-dcd8-7744-8222-ec76afe04ccd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fb94e-dcd8-72bf-ad5b-1dfa2b9ddf10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019fb94e-dcd8-72bf-ad5b-1dfa2b9ddf10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019fb94e-dcd8-7337-85dc-240cdb82b1c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019fb94e-dcd8-7337-85dc-240cdb82b1c6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RestructuringAndAssetImpairmentLosses_019fb94e-dcd8-716c-9065-0986ae41bacd" xlink:href="xyl-20260930.xsd#xyl_RestructuringAndAssetImpairmentLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_xyl_RestructuringAndAssetImpairmentLosses_019fb94e-dcd8-716c-9065-0986ae41bacd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fb94e-dcd8-70b8-861e-1247f6f85327" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_OperatingIncomeLoss_019fb94e-dcd8-70b8-861e-1247f6f85327" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fb94e-dcd8-7ec6-b394-2150cd6a1b2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fb94e-dcd8-7ec6-b394-2150cd6a1b2c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019fb94e-dcd8-7087-8ec8-221fb8d6f020" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019fb94e-dcd8-7087-8ec8-221fb8d6f020" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_019fb94e-dcd8-7bd9-a511-16bbc4068732" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_019fb94e-dcd8-7bd9-a511-16bbc4068732" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a178a6-94e4-7e50-9a8c-e9c5b1864a75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a178a6-94e4-7e50-9a8c-e9c5b1864a75" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019fb94e-dcd8-7ced-a1b8-80b105652343" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019fb94e-dcd8-7ced-a1b8-80b105652343" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019fb94e-dcd8-79f5-8015-c0d2059bfbf1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_ProfitLoss_019fb94e-dcd8-79f5-8015-c0d2059bfbf1" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019fb94e-dcd8-7086-b73b-99a528c36178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019fb94e-dcd8-7086-b73b-99a528c36178" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fb94e-dcd8-728d-965c-b149f5eaea19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_NetIncomeLoss_019fb94e-dcd8-728d-965c-b149f5eaea19" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019fb94e-dcd8-77c0-9b08-8665ddbc4377" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019fb94e-dcd8-77c0-9b08-8665ddbc4377" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019fb94e-dcd8-7447-8dde-8921f07ce8aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019fb94e-dcd8-77c0-9b08-8665ddbc4377" xlink:to="loc_us-gaap_EarningsPerShareBasic_019fb94e-dcd8-7447-8dde-8921f07ce8aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019fb94e-dcd8-739a-b2b4-e23d889d72c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019fb94e-dcd8-77c0-9b08-8665ddbc4377" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019fb94e-dcd8-739a-b2b4-e23d889d72c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019fb94e-dcd8-7e36-bfdc-d91b8e2bb9f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019fb94e-dcd8-7e36-bfdc-d91b8e2bb9f8" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019fb94e-dcd8-7ed9-95d9-a0d7e1e8ef1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fb94e-dcd8-75bb-819a-a4b353ea1abd" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019fb94e-dcd8-7ed9-95d9-a0d7e1e8ef1f" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/AcquisitionsandDivestituresDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#AcquisitionsandDivestituresDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/AcquisitionsandDivestituresDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_01a16594-d80e-7c9f-94be-3d5754a803a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_01a16594-d80e-7c9f-94be-3d5754a803a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-7c9f-94be-3d5754a803a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a16594-d80e-7c9f-94be-3d5754a803a3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-7c9f-94be-3d5754a803a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a16594-d80e-7c9f-94be-3d5754a803a3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_CornellPumpAndRoperPumpMember_01a16595-eea2-7959-a0d0-59525c02d545" xlink:href="xyl-20260930.xsd#xyl_CornellPumpAndRoperPumpMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_CornellPumpAndRoperPumpMember_01a16595-eea2-7959-a0d0-59525c02d545" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterFleetIntermediateHoldingsInc.Member_01a16594-d80e-7b4d-9826-47b7e0fe1d8e" xlink:href="xyl-20260930.xsd#xyl_WaterFleetIntermediateHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_WaterFleetIntermediateHoldingsInc.Member_01a16594-d80e-7b4d-9826-47b7e0fe1d8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_March2026AcquisitionMember_01a16594-d80e-78b7-8589-f649aa82cea4" xlink:href="xyl-20260930.xsd#xyl_March2026AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_March2026AcquisitionMember_01a16594-d80e-78b7-8589-f649aa82cea4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TriOSMessUndDatentechnikGmbHMember_01a16594-ed6d-7917-9a07-b3f42e93beea" xlink:href="xyl-20260930.xsd#xyl_TriOSMessUndDatentechnikGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_TriOSMessUndDatentechnikGmbHMember_01a16594-ed6d-7917-9a07-b3f42e93beea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_PacMachineMember_01a16595-03f3-7381-ad7b-7777458ce808" xlink:href="xyl-20260930.xsd#xyl_PacMachineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_PacMachineMember_01a16595-03f3-7381-ad7b-7777458ce808" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EMXHoldingsInc.Member_01a16595-03f3-7978-93c1-d033699b4d3b" xlink:href="xyl-20260930.xsd#xyl_EMXHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_EMXHoldingsInc.Member_01a16595-03f3-7978-93c1-d033699b4d3b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SimplyCleanAirAndWaterIncMember_01a16595-1d03-7de7-9cc9-31d6382a2bb5" xlink:href="xyl-20260930.xsd#xyl_SimplyCleanAirAndWaterIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a16594-d80e-717a-9ab8-04366df78ac9" xlink:to="loc_xyl_SimplyCleanAirAndWaterIncMember_01a16595-1d03-7de7-9cc9-31d6382a2bb5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_01a16595-1d03-7880-b6d8-c09868cf7179" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:to="loc_us-gaap_AssetAcquisitionAxis_01a16595-1d03-7880-b6d8-c09868cf7179" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a16595-1d03-7880-b6d8-c09868cf7179_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a16595-1d03-7880-b6d8-c09868cf7179" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a16595-1d03-7880-b6d8-c09868cf7179_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a16595-1d03-7383-99ea-4dc0c5a05588" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a16595-1d03-7880-b6d8-c09868cf7179" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a16595-1d03-7383-99ea-4dc0c5a05588" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_VacomSystemsLLCMember_01a16595-1d03-74cd-954f-f7ad53b87f7c" xlink:href="xyl-20260930.xsd#xyl_VacomSystemsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_01a16595-1d03-7383-99ea-4dc0c5a05588" xlink:to="loc_xyl_VacomSystemsLLCMember_01a16595-1d03-74cd-954f-f7ad53b87f7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a16595-1d03-71ad-b48c-47174e360b0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a16595-1d03-71ad-b48c-47174e360b0d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a16595-1d03-71ad-b48c-47174e360b0d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a16595-1d03-71ad-b48c-47174e360b0d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a16595-1d03-71ad-b48c-47174e360b0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a16595-1d03-748b-9bd4-2140bcbd8a42" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a16595-1d03-71ad-b48c-47174e360b0d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a16595-1d03-748b-9bd4-2140bcbd8a42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_01a16595-1d03-73f8-9235-2e3a2163675f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a16595-1d03-748b-9bd4-2140bcbd8a42" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_01a16595-1d03-73f8-9235-2e3a2163675f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a16595-322a-7030-beeb-745bca743a79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a16595-322a-7030-beeb-745bca743a79" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a16595-322a-7030-beeb-745bca743a79_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a16595-322a-7030-beeb-745bca743a79" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a16595-322a-7030-beeb-745bca743a79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a16595-322a-7491-b720-5b5f511cb6ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a16595-322a-7030-beeb-745bca743a79" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a16595-322a-7491-b720-5b5f511cb6ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a16595-322a-7f0e-bcb6-be9a6596e5b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a16595-322a-7491-b720-5b5f511cb6ad" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a16595-322a-7f0e-bcb6-be9a6596e5b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a16595-322a-72ff-b4e3-e2b0faeb5f72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a16594-d80e-758e-a30b-aaa9c442ea1b" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a16595-322a-72ff-b4e3-e2b0faeb5f72" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-72ff-b4e3-e2b0faeb5f72_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a16595-322a-72ff-b4e3-e2b0faeb5f72" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-72ff-b4e3-e2b0faeb5f72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-7760-9bc7-63e1222efda3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a16595-322a-72ff-b4e3-e2b0faeb5f72" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-7760-9bc7-63e1222efda3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_InternationalMeteringBusinessMember_01a16595-322a-7bae-b971-21b49ecc05ad" xlink:href="xyl-20260930.xsd#xyl_InternationalMeteringBusinessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-7760-9bc7-63e1222efda3" xlink:to="loc_xyl_InternationalMeteringBusinessMember_01a16595-322a-7bae-b971-21b49ecc05ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherDivestituresMember_01a16595-322a-780d-9cb1-bcfe1a1214b9" xlink:href="xyl-20260930.xsd#xyl_OtherDivestituresMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-7760-9bc7-63e1222efda3" xlink:to="loc_xyl_OtherDivestituresMember_01a16595-322a-780d-9cb1-bcfe1a1214b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EvoquaMagnetoMember_01a16595-322a-749f-ba80-61e94368c333" xlink:href="xyl-20260930.xsd#xyl_EvoquaMagnetoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a16595-322a-7760-9bc7-63e1222efda3" xlink:to="loc_xyl_EvoquaMagnetoMember_01a16595-322a-749f-ba80-61e94368c333" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_01a16594-d80e-7a03-b4bb-5c4279969b5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_01a16594-d80e-7a03-b4bb-5c4279969b5a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a16594-d80e-7ee6-a77e-ca9466bc0794" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a16594-d80e-7ee6-a77e-ca9466bc0794" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a16594-ed6d-78d4-81fd-f616e30fd582" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_Goodwill_01a16594-ed6d-78d4-81fd-f616e30fd582" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_01a16594-ed6d-70bf-8904-4ea3575db1c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_01a16594-ed6d-70bf-8904-4ea3575db1c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_01a16594-ed6d-7fa2-bfef-a3115a7c06f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_01a16594-ed6d-7fa2-bfef-a3115a7c06f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_01a16594-ed6d-7423-809d-5be69691bc8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_01a16594-ed6d-7423-809d-5be69691bc8a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_PaymentsToAcquireBusinessGrossAtClosing_01a16594-ed6d-778a-9c1b-0bd2b0a259f6" xlink:href="xyl-20260930.xsd#xyl_PaymentsToAcquireBusinessGrossAtClosing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_PaymentsToAcquireBusinessGrossAtClosing_01a16594-ed6d-778a-9c1b-0bd2b0a259f6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_PaymentsToAcquireBusinessNetOfCashAcquiredAtClosing_01a16594-ed6d-72dc-92e3-c9f18ae3c745" xlink:href="xyl-20260930.xsd#xyl_PaymentsToAcquireBusinessNetOfCashAcquiredAtClosing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_PaymentsToAcquireBusinessNetOfCashAcquiredAtClosing_01a16594-ed6d-72dc-92e3-c9f18ae3c745" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_01a16594-ed6d-718f-b57b-6218d1c420a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_01a16594-ed6d-718f-b57b-6218d1c420a7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_BusinessCombinationConsiderationTransferredSettlementOfLiability_01a16595-03f3-702c-824c-2d67ac738107" xlink:href="xyl-20260930.xsd#xyl_BusinessCombinationConsiderationTransferredSettlementOfLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_BusinessCombinationConsiderationTransferredSettlementOfLiability_01a16595-03f3-702c-824c-2d67ac738107" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_BusinessCombinationRemainingConsiderationToBePaid_01a16595-03f3-7660-a634-8ce0e9a0d56d" xlink:href="xyl-20260930.xsd#xyl_BusinessCombinationRemainingConsiderationToBePaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_BusinessCombinationRemainingConsiderationToBePaid_01a16595-03f3-7660-a634-8ce0e9a0d56d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_BusinessCombinationRemainingConsiderationToBePaidPeriod_01a16595-03f3-7c99-bb6d-c357f0abd7f7" xlink:href="xyl-20260930.xsd#xyl_BusinessCombinationRemainingConsiderationToBePaidPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_BusinessCombinationRemainingConsiderationToBePaidPeriod_01a16595-03f3-7c99-bb6d-c357f0abd7f7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_BusinessCombinationNumberOfEmployees_01a16595-1d03-72bb-82ae-a7461421e160" xlink:href="xyl-20260930.xsd#xyl_BusinessCombinationNumberOfEmployees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_BusinessCombinationNumberOfEmployees_01a16595-1d03-72bb-82ae-a7461421e160" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_01a16595-1d03-78bf-90ca-826aaa02a2e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_01a16595-1d03-78bf-90ca-826aaa02a2e4" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_PaymentsForAssetAcquisitionAtClosing_01a16595-1d03-7c08-881c-9693c593e316" xlink:href="xyl-20260930.xsd#xyl_PaymentsForAssetAcquisitionAtClosing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_PaymentsForAssetAcquisitionAtClosing_01a16595-1d03-7c08-881c-9693c593e316" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AssetAcquisitionRoyaltyOnRevenuePercentage_01a16595-1d03-7520-9ce9-f2a677e58599" xlink:href="xyl-20260930.xsd#xyl_AssetAcquisitionRoyaltyOnRevenuePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_AssetAcquisitionRoyaltyOnRevenuePercentage_01a16595-1d03-7520-9ce9-f2a677e58599" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AssetAcquisitionRoyaltyOnRevenuePeriodAfterAcquisition_01a16595-1d03-7a6f-b42e-fbe847a402e8" xlink:href="xyl-20260930.xsd#xyl_AssetAcquisitionRoyaltyOnRevenuePeriodAfterAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_AssetAcquisitionRoyaltyOnRevenuePeriodAfterAcquisition_01a16595-1d03-7a6f-b42e-fbe847a402e8" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AssetAcquisitionRoyaltyOnRevenueMaximum_01a16595-1d03-799d-9b71-7ce04cd1d3e8" xlink:href="xyl-20260930.xsd#xyl_AssetAcquisitionRoyaltyOnRevenueMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_AssetAcquisitionRoyaltyOnRevenueMaximum_01a16595-1d03-799d-9b71-7ce04cd1d3e8" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_01a16595-1d03-7f9a-9d61-eaef76b6d7d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_01a16595-1d03-7f9a-9d61-eaef76b6d7d5" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a16595-322a-76d1-9de1-408fb8a04b36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a16595-322a-76d1-9de1-408fb8a04b36" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationReceivedNet_01a16595-322a-7aed-9619-8219d147ef02" xlink:href="xyl-20260930.xsd#xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationReceivedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationReceivedNet_01a16595-322a-7aed-9619-8219d147ef02" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_01a16595-322a-79d8-9dd2-00ba66bbbb49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_01a16595-322a-79d8-9dd2-00ba66bbbb49" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_01a16595-322a-7662-ab69-f4f3cd7106ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinessesNetOfCashDivested_01a16595-322a-7662-ab69-f4f3cd7106ab" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationNoteReceivable_01a16595-322a-76fd-b52d-f202122968fd" xlink:href="xyl-20260930.xsd#xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationNoteReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_DisposalGroupIncludingDiscontinuedOperationConsiderationNoteReceivable_01a16595-322a-76fd-b52d-f202122968fd" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_01a16595-322a-78e0-b62f-24837be80e76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_01a16595-322a-78e0-b62f-24837be80e76" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment_01a16595-322a-7e76-a5a7-fc767e145067" xlink:href="xyl-20260930.xsd#xyl_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a16594-d80e-70ca-a6a6-8eb80ce28ab2" xlink:to="loc_xyl_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment_01a16595-322a-7e76-a5a7-fc767e145067" xlink:type="arc" order="25"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RestructuringandAssetImpairmentChargesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_01a155dd-be2e-7e39-bad9-b10a91b231b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_01a155dd-be2e-71d3-8178-683900ad5683" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_01a155dd-be2e-7e39-bad9-b10a91b231b4" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_01a155dd-be2e-71d3-8178-683900ad5683" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_01a155e4-5dcc-7917-87c2-78998d140534" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_01a155dd-be2e-71d3-8178-683900ad5683" xlink:to="loc_us-gaap_RestructuringPlanAxis_01a155e4-5dcc-7917-87c2-78998d140534" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_01a155e4-5dcc-7917-87c2-78998d140534_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_01a155e4-5dcc-7917-87c2-78998d140534" xlink:to="loc_us-gaap_RestructuringPlanDomain_01a155e4-5dcc-7917-87c2-78998d140534_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_01a155e4-5dcc-7f68-8025-1f0f388667a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_01a155e4-5dcc-7917-87c2-78998d140534" xlink:to="loc_us-gaap_RestructuringPlanDomain_01a155e4-5dcc-7f68-8025-1f0f388667a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ActionsCommencedPriorTo2024Member_01a155e4-5dcc-72c5-ab62-ff6c6628865a" xlink:href="xyl-20260930.xsd#xyl_ActionsCommencedPriorTo2024Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_01a155e4-5dcc-7f68-8025-1f0f388667a8" xlink:to="loc_xyl_ActionsCommencedPriorTo2024Member_01a155e4-5dcc-72c5-ab62-ff6c6628865a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_01a155dd-be2e-7eaa-ab3d-b6bf5669a871" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_01a155dd-be2e-7e39-bad9-b10a91b231b4" xlink:to="loc_us-gaap_RestructuringCharges_01a155dd-be2e-7eaa-ab3d-b6bf5669a871" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_01a155e4-5dcc-746f-bbde-a2f70d0d43b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_01a155dd-be2e-7e39-bad9-b10a91b231b4" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_01a155e4-5dcc-746f-bbde-a2f70d0d43b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_01a155e4-5dcc-70c4-b703-03f4a8890a6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_01a155dd-be2e-7e39-bad9-b10a91b231b4" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_01a155e4-5dcc-70c4-b703-03f4a8890a6b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesComponentsofRestructuringChargesandSegmentAllocationDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RestructuringandAssetImpairmentChargesComponentsofRestructuringChargesandSegmentAllocationDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesComponentsofRestructuringChargesandSegmentAllocationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7fe4-bbdc-eb324b463505" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7fe4-bbdc-eb324b463505" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-776e-931a-a7e9bd671af8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7fe4-bbdc-eb324b463505" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-776e-931a-a7e9bd671af8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-776e-931a-a7e9bd671af8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-776e-931a-a7e9bd671af8" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-776e-931a-a7e9bd671af8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-776e-931a-a7e9bd671af8" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-dd80-7a75-9f7f-da884a0627f7" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-dd80-7a75-9f7f-da884a0627f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7907-9683-416d562f907c" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7907-9683-416d562f907c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7a6e-b230-ce649f3c07df" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7a6e-b230-ce649f3c07df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateAndOtherMember_019fb94e-dd80-79b1-9529-0a799570a032" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:to="loc_us-gaap_CorporateAndOtherMember_019fb94e-dd80-79b1-9529-0a799570a032" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a15ffe-0cc8-7c3c-a2ac-39ceec05cb46" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-74af-a8b9-c904edd01119" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a15ffe-0cc8-7c3c-a2ac-39ceec05cb46" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeveranceCosts1_019fb94e-dd80-7a43-b1a6-8a60c466af39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeveranceCosts1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_us-gaap_SeveranceCosts1_019fb94e-dd80-7a43-b1a6-8a60c466af39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RestructuringReserveAssetImpairment_019fb94e-dd80-7295-8e28-029b2fc6c652" xlink:href="xyl-20260930.xsd#xyl_RestructuringReserveAssetImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_xyl_RestructuringReserveAssetImpairment_019fb94e-dd80-7295-8e28-029b2fc6c652" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAccrualAdjustment1_019fb94e-dd80-7710-ac29-647fc074037f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveAccrualAdjustment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_us-gaap_RestructuringReserveAccrualAdjustment1_019fb94e-dd80-7710-ac29-647fc074037f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019fb94e-dd80-74cd-a741-3f0ac9200a6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_us-gaap_RestructuringCharges_019fb94e-dd80-74cd-a741-3f0ac9200a6d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_019fb94e-dd80-7e97-822e-544475d08d02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_us-gaap_AssetImpairmentCharges_019fb94e-dd80-7e97-822e-544475d08d02" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AssetImpairmentandRestructuringCharges_019fb94e-dd80-7544-9ca6-cb6298a3e252" xlink:href="xyl-20260930.xsd#xyl_AssetImpairmentandRestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7020-be3f-c9213965a39f" xlink:to="loc_xyl_AssetImpairmentandRestructuringCharges_019fb94e-dd80-7544-9ca6-cb6298a3e252" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesRestructuringReserveRollforwardDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RestructuringandAssetImpairmentChargesRestructuringReserveRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesRestructuringReserveRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-79d3-8681-3160310a863f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-74a5-94bb-c328c0f6645d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-79d3-8681-3160310a863f" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-74a5-94bb-c328c0f6645d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7618-a0b1-a6a6a0754ab8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-74a5-94bb-c328c0f6645d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7618-a0b1-a6a6a0754ab8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-7618-a0b1-a6a6a0754ab8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7618-a0b1-a6a6a0754ab8" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-7618-a0b1-a6a6a0754ab8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7618-a0b1-a6a6a0754ab8" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-dd80-7a4e-b66f-ba206cfa5b59" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-dd80-7a4e-b66f-ba206cfa5b59" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RegionalSellingLocationsMember_019fb94e-dd80-7f97-8ca8-af92fe589689" xlink:href="xyl-20260930.xsd#xyl_RegionalSellingLocationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_xyl_RegionalSellingLocationsMember_019fb94e-dd80-7f97-8ca8-af92fe589689" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateAndOtherMember_019fb94e-dd80-7ee2-9ae1-56d6906a6ae6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_us-gaap_CorporateAndOtherMember_019fb94e-dd80-7ee2-9ae1-56d6906a6ae6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7d60-9a12-87b117039430" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7d60-9a12-87b117039430" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7403-8755-e265fb09ce2c" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7403-8755-e265fb09ce2c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a15fff-533e-7fdb-8792-b7de4f226eca" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7ca7-9d5a-981cc034549c" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a15fff-533e-7fdb-8792-b7de4f226eca" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-79d3-8681-3160310a863f" xlink:to="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_019fb94e-dd80-714d-b0e0-397c8a5e8dbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:to="loc_us-gaap_RestructuringReserve_019fb94e-dd80-714d-b0e0-397c8a5e8dbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019fb94e-dd80-717b-9da0-754881a95a21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:to="loc_us-gaap_RestructuringCharges_019fb94e-dd80-717b-9da0-754881a95a21" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_019fb94e-dd80-7d62-b874-dd6f5e89daf3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:to="loc_us-gaap_PaymentsForRestructuring_019fb94e-dd80-7d62-b874-dd6f5e89daf3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RestructuringReserveAssetImpairment_019fb94e-dd80-7501-bab8-9c623457018b" xlink:href="xyl-20260930.xsd#xyl_RestructuringReserveAssetImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:to="loc_xyl_RestructuringReserveAssetImpairment_019fb94e-dd80-7501-bab8-9c623457018b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveTranslationAndOtherAdjustment_019fb94e-dd80-7fc9-b420-3cd904088a9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserveTranslationAndOtherAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_019fb94e-dd80-71fa-966b-eb0b6ebd0ab7" xlink:to="loc_us-gaap_RestructuringReserveTranslationAndOtherAdjustment_019fb94e-dd80-7fc9-b420-3cd904088a9c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_019fb94e-dd80-7ce1-9ff6-666bd5f2663f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringReserve"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesEstimatedRestructuringCostsDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RestructuringandAssetImpairmentChargesEstimatedRestructuringCostsDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RestructuringandAssetImpairmentChargesEstimatedRestructuringCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7838-85ae-3392bf48d146" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7344-8b11-937d1d629ef4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7838-85ae-3392bf48d146" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7344-8b11-937d1d629ef4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019fb94e-dd80-7b34-9b00-c5045fdf24b5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7344-8b11-937d1d629ef4" xlink:to="loc_srt_ConsolidationItemsAxis_019fb94e-dd80-7b34-9b00-c5045fdf24b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7b34-9b00-c5045fdf24b5_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019fb94e-dd80-7b34-9b00-c5045fdf24b5" xlink:to="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7b34-9b00-c5045fdf24b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7983-ba1f-f4f17a69c19f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019fb94e-dd80-7b34-9b00-c5045fdf24b5" xlink:to="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7983-ba1f-f4f17a69c19f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019fb94e-dd80-7d1d-a7f1-8f6a7d883bae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7983-ba1f-f4f17a69c19f" xlink:to="loc_us-gaap_OperatingSegmentsMember_019fb94e-dd80-7d1d-a7f1-8f6a7d883bae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019fb94e-dd80-7969-a7fa-22c5d1d89d91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019fb94e-dd80-7983-ba1f-f4f17a69c19f" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019fb94e-dd80-7969-a7fa-22c5d1d89d91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7da3-b24f-633ee2f5231a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7344-8b11-937d1d629ef4" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7da3-b24f-633ee2f5231a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-7da3-b24f-633ee2f5231a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7da3-b24f-633ee2f5231a" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-7da3-b24f-633ee2f5231a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-7da3-b24f-633ee2f5231a" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-dd80-7855-97e6-beca8f71a160" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-dd80-7855-97e6-beca8f71a160" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7139-ae6e-86d9bcca8b54" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7139-ae6e-86d9bcca8b54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_IntegratedSolutionsAndServicesMember_019fb94e-dd80-737b-accb-28386a234f3d" xlink:href="xyl-20260930.xsd#xyl_IntegratedSolutionsAndServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:to="loc_xyl_IntegratedSolutionsAndServicesMember_019fb94e-dd80-737b-accb-28386a234f3d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a15fff-0f91-7ba9-b654-8b7f7bf171b7" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-7d47-9c30-50a3b9102c16" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a15fff-0f91-7ba9-b654-8b7f7bf171b7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_01a155e3-cf93-77eb-af14-b130522cab46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019fb94e-dd80-7344-8b11-937d1d629ef4" xlink:to="loc_us-gaap_RestructuringPlanAxis_01a155e3-cf93-77eb-af14-b130522cab46" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-77eb-af14-b130522cab46_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_01a155e3-cf93-77eb-af14-b130522cab46" xlink:to="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-77eb-af14-b130522cab46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-7288-aa61-3d3f9a3aecf0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_01a155e3-cf93-77eb-af14-b130522cab46" xlink:to="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-7288-aa61-3d3f9a3aecf0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ActionsCommencedIn2026Member_01a155e4-1208-7af8-900e-f9988d4e5d04" xlink:href="xyl-20260930.xsd#xyl_ActionsCommencedIn2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-7288-aa61-3d3f9a3aecf0" xlink:to="loc_xyl_ActionsCommencedIn2026Member_01a155e4-1208-7af8-900e-f9988d4e5d04" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ActionsCommencedIn2025Member_01a155e3-cf93-7eab-afcf-eecd05371bcf" xlink:href="xyl-20260930.xsd#xyl_ActionsCommencedIn2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_01a155e3-cf93-7288-aa61-3d3f9a3aecf0" xlink:to="loc_xyl_ActionsCommencedIn2025Member_01a155e3-cf93-7eab-afcf-eecd05371bcf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_019fb94e-dd80-7d5c-81ae-3a2901a428bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostExpectedCost1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7838-85ae-3392bf48d146" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_019fb94e-dd80-7d5c-81ae-3a2901a428bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostIncurredCost_019fb94e-dd80-78e1-84f8-315f7807bb68" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostIncurredCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7838-85ae-3392bf48d146" xlink:to="loc_us-gaap_RestructuringAndRelatedCostIncurredCost_019fb94e-dd80-78e1-84f8-315f7807bb68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_019fb94e-dd80-7b1f-a963-76a6ca565644" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019fb94e-dd80-7838-85ae-3392bf48d146" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_019fb94e-dd80-7b1f-a963-76a6ca565644" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RevenueDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RevenueDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019fb94e-dd80-7792-ae09-20f1783d9131" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019fb94e-dd80-7015-82fd-2a7af3996c74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019fb94e-dd80-7792-ae09-20f1783d9131" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019fb94e-dd80-7015-82fd-2a7af3996c74" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-72ee-91bd-8a9bf82643a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019fb94e-dd80-7015-82fd-2a7af3996c74" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-72ee-91bd-8a9bf82643a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-72ee-91bd-8a9bf82643a7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-72ee-91bd-8a9bf82643a7" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-72ee-91bd-8a9bf82643a7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd80-72ee-91bd-8a9bf82643a7" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a155ff-4f17-7ac3-8739-45a163b094c5" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a155ff-4f17-7ac3-8739-45a163b094c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-dd80-7403-a650-133e85e84c37" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-dd80-7403-a650-133e85e84c37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7e97-bf1a-c4387caabd84" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd80-7e97-bf1a-c4387caabd84" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7f2d-bd8e-315bd991ffbd" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd80-71a8-bb5b-13964ee63b86" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd80-7f2d-bd8e-315bd991ffbd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019fb94e-dd80-78c7-ba34-9d8e9336c489" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019fb94e-dd80-7015-82fd-2a7af3996c74" xlink:to="loc_srt_ProductOrServiceAxis_019fb94e-dd80-78c7-ba34-9d8e9336c489" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-78c7-ba34-9d8e9336c489_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019fb94e-dd80-78c7-ba34-9d8e9336c489" xlink:to="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-78c7-ba34-9d8e9336c489_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019fb94e-dd80-78c7-ba34-9d8e9336c489" xlink:to="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TransportMember_019fb94e-dd80-7a23-ab6f-d7b99152686c" xlink:href="xyl-20260930.xsd#xyl_TransportMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_TransportMember_019fb94e-dd80-7a23-ab6f-d7b99152686c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TreatmentMember_019fb94e-dd80-7b33-847d-1c7f670300b9" xlink:href="xyl-20260930.xsd#xyl_TreatmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_TreatmentMember_019fb94e-dd80-7b33-847d-1c7f670300b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_CommercialBuildingServicesMember_019fb94e-dd80-7f0c-b0d2-0ce1f81bb857" xlink:href="xyl-20260930.xsd#xyl_CommercialBuildingServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_CommercialBuildingServicesMember_019fb94e-dd80-7f0c-b0d2-0ce1f81bb857" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_IndustrialWaterMember_019fb94e-dd80-7325-89b1-03f1cc498c43" xlink:href="xyl-20260930.xsd#xyl_IndustrialWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_IndustrialWaterMember_019fb94e-dd80-7325-89b1-03f1cc498c43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SmartMeteringOtherMember_019fb94e-dd80-7bc3-886f-f657f3d4f7e6" xlink:href="xyl-20260930.xsd#xyl_SmartMeteringOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_SmartMeteringOtherMember_019fb94e-dd80-7bc3-886f-f657f3d4f7e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AnalyticsMember_019fb94e-dd80-7008-acb8-ab45aba82c46" xlink:href="xyl-20260930.xsd#xyl_AnalyticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_AnalyticsMember_019fb94e-dd80-7008-acb8-ab45aba82c46" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_CapitalOtherMember_019fb94e-dd80-73d6-85b8-71dd242ef22a" xlink:href="xyl-20260930.xsd#xyl_CapitalOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_CapitalOtherMember_019fb94e-dd80-73d6-85b8-71dd242ef22a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ServicesMember_019fb94e-dd80-7334-b75a-8de323318593" xlink:href="xyl-20260930.xsd#xyl_ServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019fb94e-dd80-7f29-a44d-93134a1a030f" xlink:to="loc_xyl_ServicesMember_019fb94e-dd80-7334-b75a-8de323318593" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019fb94e-dd80-72cd-b86e-a8a68fa15adc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019fb94e-dd80-7015-82fd-2a7af3996c74" xlink:to="loc_srt_StatementGeographicalAxis_019fb94e-dd80-72cd-b86e-a8a68fa15adc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-72cd-b86e-a8a68fa15adc_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019fb94e-dd80-72cd-b86e-a8a68fa15adc" xlink:to="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-72cd-b86e-a8a68fa15adc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019fb94e-dd80-72cd-b86e-a8a68fa15adc" xlink:to="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019fb94e-dd80-7642-8f19-82ad6c9fb18c" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:to="loc_country_US_019fb94e-dd80-7642-8f19-82ad6c9fb18c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019fb94e-dd80-736a-b44b-35828c1b1ff5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:to="loc_srt_EuropeMember_019fb94e-dd80-736a-b44b-35828c1b1ff5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EmergingMarketsMember_019fb94e-dd80-7182-901f-dc6e8a3f71de" xlink:href="xyl-20260930.xsd#xyl_EmergingMarketsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:to="loc_xyl_EmergingMarketsMember_019fb94e-dd80-7182-901f-dc6e8a3f71de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherGeographicalRegionsMember_019fb94e-dd80-70d8-b5b4-ec5cb09f9104" xlink:href="xyl-20260930.xsd#xyl_OtherGeographicalRegionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019fb94e-dd80-75a6-9c77-4f911f3fe8da" xlink:to="loc_xyl_OtherGeographicalRegionsMember_019fb94e-dd80-70d8-b5b4-ec5cb09f9104" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019fb94e-dd80-7745-941c-e06056a00ded" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019fb94e-dd80-7792-ae09-20f1783d9131" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019fb94e-dd80-7745-941c-e06056a00ded" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_01a155dc-341c-7f96-924d-5fd7dfcca286" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019fb94e-dd80-7792-ae09-20f1783d9131" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncome_01a155dc-341c-7f96-924d-5fd7dfcca286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019fb94e-dd80-7e7a-bcde-69b72a23e6f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019fb94e-dd80-7792-ae09-20f1783d9131" xlink:to="loc_us-gaap_Revenues_019fb94e-dd80-7e7a-bcde-69b72a23e6f0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/EarningsPerShareCalculationofEPSDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#EarningsPerShareCalculationofEPSDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/EarningsPerShareCalculationofEPSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedLineItems_019fb94e-dd81-7586-b32d-5533f9845c68" xlink:href="xyl-20260930.xsd#xyl_ScheduleOfEarningsPerShareBasicAndDilutedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedTable_019fb94e-dd81-7502-91b2-89240e7d1839" xlink:href="xyl-20260930.xsd#xyl_ScheduleOfEarningsPerShareBasicAndDilutedTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedLineItems_019fb94e-dd81-7586-b32d-5533f9845c68" xlink:to="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedTable_019fb94e-dd81-7502-91b2-89240e7d1839" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019fb94e-dd81-76be-95a5-d96f279a0235" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedTable_019fb94e-dd81-7502-91b2-89240e7d1839" xlink:to="loc_us-gaap_AwardTypeAxis_019fb94e-dd81-76be-95a5-d96f279a0235" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-76be-95a5-d96f279a0235_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-dd81-76be-95a5-d96f279a0235" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-76be-95a5-d96f279a0235_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-7f94-ba6d-baefc5d4d449" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-dd81-76be-95a5-d96f279a0235" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-7f94-ba6d-baefc5d4d449" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019fb94e-dd81-7102-841b-3514e37c3714" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-7f94-ba6d-baefc5d4d449" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019fb94e-dd81-7102-841b-3514e37c3714" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019fb94e-dd81-7896-ac72-86840dc6d868" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-dd81-7f94-ba6d-baefc5d4d449" xlink:to="loc_us-gaap_RestrictedStockMember_019fb94e-dd81-7896-ac72-86840dc6d868" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_xyl_ScheduleOfEarningsPerShareBasicAndDilutedLineItems_019fb94e-dd81-7586-b32d-5533f9845c68" xlink:to="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fb94e-dd81-70c1-bd99-f75fe12a8968" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_NetIncomeLoss_019fb94e-dd81-70c1-bd99-f75fe12a8968" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019fb94e-dd81-7ba6-a1f6-c89763559ac6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_ProfitLoss_019fb94e-dd81-7ba6-a1f6-c89763559ac6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019fb94e-dd81-7168-9ec1-8531eb312da3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019fb94e-dd81-7168-9ec1-8531eb312da3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesIssuedBasic_019fb94e-dd81-7776-9e4e-3da3af3d3711" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesIssuedBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019fb94e-dd81-7168-9ec1-8531eb312da3" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesIssuedBasic_019fb94e-dd81-7776-9e4e-3da3af3d3711" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WeightedAverageNumberOfSharesParticipatingSecurities_019fb94e-dd81-715b-b556-253d00732a8b" xlink:href="xyl-20260930.xsd#xyl_WeightedAverageNumberOfSharesParticipatingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019fb94e-dd81-7168-9ec1-8531eb312da3" xlink:to="loc_xyl_WeightedAverageNumberOfSharesParticipatingSecurities_019fb94e-dd81-715b-b556-253d00732a8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019fb94e-dd81-75b5-a72e-cbbdc092fcf1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_019fb94e-dd81-7168-9ec1-8531eb312da3" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019fb94e-dd81-75b5-a72e-cbbdc092fcf1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_019fb94e-dd81-721f-b22e-811677d43934" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_019fb94e-dd81-721f-b22e-811677d43934" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019fb94e-dd81-75e9-ab67-59d830cb0a3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_019fb94e-dd81-721f-b22e-811677d43934" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019fb94e-dd81-75e9-ab67-59d830cb0a3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019fb94e-dd81-79ea-8ff2-77e9d940b806" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_019fb94e-dd81-721f-b22e-811677d43934" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019fb94e-dd81-79ea-8ff2-77e9d940b806" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019fb94e-dd81-72a8-bd6d-d9ac58556186" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_EarningsPerShareBasic_019fb94e-dd81-72a8-bd6d-d9ac58556186" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019fb94e-dd81-78e8-b906-b9fe1d4fa9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareReconciliationAbstract_019fb94e-dd81-70a8-898f-9eec2ccc8dea" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019fb94e-dd81-78e8-b906-b9fe1d4fa9a9" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/EarningsPerShareSummaryofAntidilutiveSecuritiesDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#EarningsPerShareSummaryofAntidilutiveSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/EarningsPerShareSummaryofAntidilutiveSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019fb94e-dd81-7da1-99c0-aab0f7612ba7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019fb94e-dd81-7e26-8b15-4531afc4cd18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019fb94e-dd81-7da1-99c0-aab0f7612ba7" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019fb94e-dd81-7e26-8b15-4531afc4cd18" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019fb94e-dd81-7ccd-929a-c8f59e865576" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019fb94e-dd81-7e26-8b15-4531afc4cd18" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019fb94e-dd81-7ccd-929a-c8f59e865576" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7ccd-929a-c8f59e865576_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019fb94e-dd81-7ccd-929a-c8f59e865576" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7ccd-929a-c8f59e865576_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7283-86b4-6a9708300592" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019fb94e-dd81-7ccd-929a-c8f59e865576" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7283-86b4-6a9708300592" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019fb94e-dd81-7af3-8283-2a44507b1f2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7283-86b4-6a9708300592" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019fb94e-dd81-7af3-8283-2a44507b1f2c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019fb94e-dd81-7550-9441-d5626262ebe9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7283-86b4-6a9708300592" xlink:to="loc_us-gaap_RestrictedStockMember_019fb94e-dd81-7550-9441-d5626262ebe9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019fb94e-dd81-7d12-9ff8-e9fefdf44cb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019fb94e-dd81-7283-86b4-6a9708300592" xlink:to="loc_us-gaap_PerformanceSharesMember_019fb94e-dd81-7d12-9ff8-e9fefdf44cb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_019fb94e-dd81-7de4-a6e7-d19b344d8be1" xlink:href="xyl-20260930.xsd#xyl_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019fb94e-dd81-7da1-99c0-aab0f7612ba7" xlink:to="loc_xyl_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_019fb94e-dd81-7de4-a6e7-d19b344d8be1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019fb94e-dd81-7ef4-80cd-c72fb0c2f6c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_xyl_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract_019fb94e-dd81-7de4-a6e7-d19b344d8be1" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019fb94e-dd81-7ef4-80cd-c72fb0c2f6c0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsRollforwardofGoodwillDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#GoodwillandOtherIntangibleAssetsRollforwardofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsRollforwardofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentLineItems_019fb94e-dd81-7107-927d-0a295930adda" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilityPropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentTable_019fb94e-dd81-73da-b39f-b1337d3510eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilityPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentLineItems_019fb94e-dd81-7107-927d-0a295930adda" xlink:to="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentTable_019fb94e-dd81-73da-b39f-b1337d3510eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd81-70e7-95ce-ee6570463696" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentTable_019fb94e-dd81-73da-b39f-b1337d3510eb" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd81-70e7-95ce-ee6570463696" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd81-70e7-95ce-ee6570463696_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd81-70e7-95ce-ee6570463696" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd81-70e7-95ce-ee6570463696_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-dd81-70e7-95ce-ee6570463696" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a1561c-a7db-790c-aa9c-6b06eedeb718" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a1561c-a7db-790c-aa9c-6b06eedeb718" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-dd81-7bbe-bac5-2ee947d0f72e" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-dd81-7bbe-bac5-2ee947d0f72e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd81-7b66-93c9-633795561ce8" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-dd81-7b66-93c9-633795561ce8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd81-743b-a5da-0b82c4a6d173" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-dd81-7136-84b1-559af9bca610" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-dd81-743b-a5da-0b82c4a6d173" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilityPropertyPlantAndEquipmentLineItems_019fb94e-dd81-7107-927d-0a295930adda" xlink:to="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019fb94e-dd81-7748-9797-754a42dbea20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:to="loc_us-gaap_Goodwill_019fb94e-dd81-7748-9797-754a42dbea20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019fb94e-dd81-7a5f-87a9-1c59a05ad92f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019fb94e-dd81-7a5f-87a9-1c59a05ad92f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_GoodwillAcquiredDuringPeriodNet_01a1561d-169c-7c88-9c59-39771ea840b5" xlink:href="xyl-20260930.xsd#xyl_GoodwillAcquiredDuringPeriodNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:to="loc_xyl_GoodwillAcquiredDuringPeriodNet_01a1561d-169c-7c88-9c59-39771ea840b5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_019fb94e-dd81-77b7-9d0a-2f5d157148da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:to="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_019fb94e-dd81-77b7-9d0a-2f5d157148da" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019fb94e-dd81-7feb-9e62-5654f007bb4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019fb94e-dd81-7432-a879-a84e154303f0" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019fb94e-dd81-7feb-9e62-5654f007bb4b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019fb94e-dd81-760d-b168-e7c62594a807" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsSummaryofOtherIntangibleAssetsDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#GoodwillandOtherIntangibleAssetsSummaryofOtherIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsSummaryofOtherIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155ef-dcdb-7a4f-82c7-a3ec1f336b93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155ef-dcdb-7a4f-82c7-a3ec1f336b93" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155ef-dcdb-7a4f-82c7-a3ec1f336b93" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a155ef-dcdb-7e85-ad15-8b4dd4597c7c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_CustomerandDistributorRelationshipsMember_01a155ef-dcdb-7036-bee8-f9893c7838fb" xlink:href="xyl-20260930.xsd#xyl_CustomerandDistributorRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:to="loc_xyl_CustomerandDistributorRelationshipsMember_01a155ef-dcdb-7036-bee8-f9893c7838fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ProprietaryTechnologyMember_01a155ef-dcdb-7c43-8d4c-20114924ee51" xlink:href="xyl-20260930.xsd#xyl_ProprietaryTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:to="loc_xyl_ProprietaryTechnologyMember_01a155ef-dcdb-7c43-8d4c-20114924ee51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_01a155ef-dcdb-7dfc-9d8b-19a927ca7736" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:to="loc_us-gaap_TrademarksMember_01a155ef-dcdb-7dfc-9d8b-19a927ca7736" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_01a155ef-dcdb-76da-aec2-106ad42b0a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_01a155ef-dcdb-76da-aec2-106ad42b0a2d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_01a155ef-dcdb-731d-a638-9b0ac41999ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a155ef-dcdb-793b-91e7-aac13eaaf5d9" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_01a155ef-dcdb-731d-a638-9b0ac41999ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_01a155f0-caab-765c-ab23-d29cbc3eace0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_01a155f0-caab-765c-ab23-d29cbc3eace0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a155ef-dcdb-7d4d-a2b2-2809b88152a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_01a155f0-caab-765c-ab23-d29cbc3eace0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a155ef-dcdb-7d4d-a2b2-2809b88152a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a155ef-dcdb-7d85-b496-4af00703e534" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_01a155f0-caab-765c-ab23-d29cbc3eace0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a155ef-dcdb-7d85-b496-4af00703e534" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a155ef-dcdb-7a18-8652-f7dc9081a0f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_01a155f0-caab-765c-ab23-d29cbc3eace0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a155ef-dcdb-7a18-8652-f7dc9081a0f7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_01a155ef-dcdb-7efe-9352-c936aa764f67" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_01a155ef-dcdb-7efe-9352-c936aa764f67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_01a155ef-dcdb-7918-964e-241c858187bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_01a155ef-dcdb-7918-964e-241c858187bf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_01a155ef-dcdb-7e1e-80eb-d47b31e16ca5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_01a155ef-dcdb-7e1e-80eb-d47b31e16ca5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareNet_01a155fe-e15e-7e06-838a-efb443011d17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedComputerSoftwareNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155ef-dcdb-7a20-8010-93d68babc932" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareNet_01a155fe-e15e-7e06-838a-efb443011d17" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#GoodwillandOtherIntangibleAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/GoodwillandOtherIntangibleAssetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155fc-267d-733c-ab5c-b0163472c0de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155fc-267d-7a8a-9cbc-37762f2368c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155fc-267d-733c-ab5c-b0163472c0de" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155fc-267d-7a8a-9cbc-37762f2368c6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a155fd-3144-7bca-97a1-60501696d09e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a155fc-267d-7a8a-9cbc-37762f2368c6" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a155fd-3144-7bca-97a1-60501696d09e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a155fd-3144-7bca-97a1-60501696d09e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a155fd-3144-7bca-97a1-60501696d09e" xlink:to="loc_us-gaap_SegmentDomain_01a155fd-3144-7bca-97a1-60501696d09e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a155fd-3144-7bca-97a1-60501696d09e" xlink:to="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementAndControlSolutionsSegmentMember_01a155fd-57be-752a-af5c-7c8b7272ebb7" xlink:href="xyl-20260930.xsd#xyl_MeasurementAndControlSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:to="loc_xyl_MeasurementAndControlSolutionsSegmentMember_01a155fd-57be-752a-af5c-7c8b7272ebb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateMember_01a155fd-87d1-730d-ac32-6c89e09931b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:to="loc_us-gaap_CorporateMember_01a155fd-87d1-730d-ac32-6c89e09931b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a155fd-d7f2-7c59-a652-cedbaf40b54f" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a155fd-d7f2-7c59-a652-cedbaf40b54f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_01a155fe-1504-7bbd-91fb-9866066d32d6" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a155fd-3144-77b9-8195-6dbd035a2817" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_01a155fe-1504-7bbd-91fb-9866066d32d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_01a155fc-267d-7aff-b4b7-aa8dac082a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155fc-267d-733c-ab5c-b0163472c0de" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_01a155fc-267d-7aff-b4b7-aa8dac082a2d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_01a155fc-d4ff-7217-a2ce-7461ef5a8f3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155fc-267d-733c-ab5c-b0163472c0de" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_01a155fc-d4ff-7217-a2ce-7461ef5a8f3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportingUnits_01a17896-4dad-78a0-81c0-56aa367b224a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a155fc-267d-733c-ab5c-b0163472c0de" xlink:to="loc_us-gaap_NumberOfReportingUnits_01a17896-4dad-78a0-81c0-56aa367b224a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/CreditFacilitiesandLongTermDebtSummaryofDebtOutstandingDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#CreditFacilitiesandLongTermDebtSummaryofDebtOutstandingDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/CreditFacilitiesandLongTermDebtSummaryofDebtOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019fb94e-de32-78da-b7fa-cf84b18036ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019fb94e-de32-7d52-8eee-9d08c14c8457" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fb94e-de32-78da-b7fa-cf84b18036ea" xlink:to="loc_us-gaap_DebtInstrumentTable_019fb94e-de32-7d52-8eee-9d08c14c8457" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019fb94e-de32-7b4f-b259-6b00b9f33aa6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019fb94e-de32-7d52-8eee-9d08c14c8457" xlink:to="loc_us-gaap_DebtInstrumentAxis_019fb94e-de32-7b4f-b259-6b00b9f33aa6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-7b4f-b259-6b00b9f33aa6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fb94e-de32-7b4f-b259-6b00b9f33aa6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-7b4f-b259-6b00b9f33aa6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fb94e-de32-7b4f-b259-6b00b9f33aa6" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwoThousandTwentySixMember_019fb94e-de32-7395-beea-a63501c03e26" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwoThousandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_SeniorNotesDueTwoThousandTwentySixMember_019fb94e-de32-7395-beea-a63501c03e26" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwentyTwentyEightMember_019fb94e-de32-71f3-aa07-826a012fde54" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwentyTwentyEightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_SeniorNotesDueTwentyTwentyEightMember_019fb94e-de32-71f3-aa07-826a012fde54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwentyThirtyOneMember_019fb94e-de32-76b5-b2a3-934bf42d8dde" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwentyThirtyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_SeniorNotesDueTwentyThirtyOneMember_019fb94e-de32-76b5-b2a3-934bf42d8dde" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwoThousandFortySixMember_019fb94e-de32-7b71-afb5-9cee2a45792a" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwoThousandFortySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_SeniorNotesDueTwoThousandFortySixMember_019fb94e-de32-7b71-afb5-9cee2a45792a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EquipmentFinancingMember_019fb94e-de32-7001-a939-fa8f6d5b7fc7" xlink:href="xyl-20260930.xsd#xyl_EquipmentFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_EquipmentFinancingMember_019fb94e-de32-7001-a939-fa8f6d5b7fc7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_019fb94e-de32-74c7-9fbf-a7a67bedef7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_019fb94e-de32-74c7-9fbf-a7a67bedef7e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.200SeniorNotesDue2033Member_01a0d4ee-4e03-7652-8b8f-90de9e4e2749" xlink:href="xyl-20260930.xsd#xyl_A5.200SeniorNotesDue2033Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_A5.200SeniorNotesDue2033Member_01a0d4ee-4e03-7652-8b8f-90de9e4e2749" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.450SeniorNotesDue2036Member_01a1659d-a17b-7487-ba15-7ed62e15f21b" xlink:href="xyl-20260930.xsd#xyl_A5.450SeniorNotesDue2036Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fb94e-de32-744f-b538-b140e45f9d4a" xlink:to="loc_xyl_A5.450SeniorNotesDue2036Member_01a1659d-a17b-7487-ba15-7ed62e15f21b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019fb94e-de32-74ba-b109-137c52d6808a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019fb94e-de32-7d52-8eee-9d08c14c8457" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019fb94e-de32-74ba-b109-137c52d6808a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-74ba-b109-137c52d6808a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fb94e-de32-74ba-b109-137c52d6808a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-74ba-b109-137c52d6808a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-7ae3-b98c-0827d266f34d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fb94e-de32-74ba-b109-137c52d6808a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-7ae3-b98c-0827d266f34d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019fb94e-de32-76a0-a5e5-c1d707c988e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-7ae3-b98c-0827d266f34d" xlink:to="loc_us-gaap_SecuredDebtMember_019fb94e-de32-76a0-a5e5-c1d707c988e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorLoansMember_01a1784a-3bd4-7419-adc0-b827cda72a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019fb94e-de32-7ae3-b98c-0827d266f34d" xlink:to="loc_us-gaap_SeniorLoansMember_01a1784a-3bd4-7419-adc0-b827cda72a8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fb94e-de32-78da-b7fa-cf84b18036ea" xlink:to="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019fb94e-de32-7c6c-ac59-a36ad9b5a950" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019fb94e-de32-7c6c-ac59-a36ad9b5a950" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019fb94e-de32-7ae7-943e-ae34bd0f5965" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019fb94e-de32-7ae7-943e-ae34bd0f5965" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019fb94e-de32-7993-af3e-49f16925d609" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_019fb94e-de32-7993-af3e-49f16925d609" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DebtInstrumentFairValueHedgeBasisAdjustments_01a17844-1913-7d28-a3f0-7cf1636e239a" xlink:href="xyl-20260930.xsd#xyl_DebtInstrumentFairValueHedgeBasisAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_xyl_DebtInstrumentFairValueHedgeBasisAdjustments_01a17844-1913-7d28-a3f0-7cf1636e239a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_019fb94e-de32-7622-8c3c-c70cba6e71e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_019fb94e-de32-7622-8c3c-c70cba6e71e3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_019fb94e-de32-71e0-a4fc-fb6e31f90899" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_ShortTermBorrowings_019fb94e-de32-71e0-a4fc-fb6e31f90899" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019fb94e-de32-7915-a6f1-f4068fd7ec01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019fb94e-de32-7915-a6f1-f4068fd7ec01" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019fb94e-de32-7f97-8442-6fa643527d8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract_019fb94e-de32-72a3-b35e-4813557bae12" xlink:to="loc_us-gaap_LongTermDebtFairValue_019fb94e-de32-7f97-8442-6fa643527d8e" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/CreditFacilitiesandLongTermDebtNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#CreditFacilitiesandLongTermDebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/CreditFacilitiesandLongTermDebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a1784f-4658-70f4-ae6b-c32e72dc88d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_DebtInstrumentTable_01a1784f-4658-70f4-ae6b-c32e72dc88d6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a1784f-4658-7b75-b0a3-bd0f578fb763" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a1784f-4658-70f4-ae6b-c32e72dc88d6" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a1784f-4658-7b75-b0a3-bd0f578fb763" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-7b75-b0a3-bd0f578fb763_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a1784f-4658-7b75-b0a3-bd0f578fb763" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-7b75-b0a3-bd0f578fb763_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a1784f-4658-7b75-b0a3-bd0f578fb763" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.250SeniorNotesDue2029Member_01a1784f-4658-7307-998b-706ac4f26ce5" xlink:href="xyl-20260930.xsd#xyl_A5.250SeniorNotesDue2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A5.250SeniorNotesDue2029Member_01a1784f-4658-7307-998b-706ac4f26ce5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.450SeniorNotesDue2032Member_01a1784f-4658-73c7-8ec0-6845458bf10f" xlink:href="xyl-20260930.xsd#xyl_A5.450SeniorNotesDue2032Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A5.450SeniorNotesDue2032Member_01a1784f-4658-73c7-8ec0-6845458bf10f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.850SeniorNotesDue2037Member_01a1784f-4658-7b3b-854a-9f504fe22db9" xlink:href="xyl-20260930.xsd#xyl_A5.850SeniorNotesDue2037Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A5.850SeniorNotesDue2037Member_01a1784f-4658-7b3b-854a-9f504fe22db9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_September2026SeniorNotesMember_01a17858-3315-7c20-bc7d-b650ed323a09" xlink:href="xyl-20260930.xsd#xyl_September2026SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_September2026SeniorNotesMember_01a17858-3315-7c20-bc7d-b650ed323a09" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_GreenBondMember_01a17858-524b-74e1-846f-f1d6ce643031" xlink:href="xyl-20260930.xsd#xyl_GreenBondMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_GreenBondMember_01a17858-524b-74e1-846f-f1d6ce643031" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.200SeniorNotesDue2033Member_01a17858-524b-7d72-b357-aa78b4339c0a" xlink:href="xyl-20260930.xsd#xyl_A5.200SeniorNotesDue2033Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A5.200SeniorNotesDue2033Member_01a17858-524b-7d72-b357-aa78b4339c0a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A5.450SeniorNotesDue2036Member_01a17858-524b-7d30-aa6c-9bacbf127af4" xlink:href="xyl-20260930.xsd#xyl_A5.450SeniorNotesDue2036Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A5.450SeniorNotesDue2036Member_01a17858-524b-7d30-aa6c-9bacbf127af4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwoThousandTwentySixMember_01a17858-524b-79e9-8938-038a04f720b0" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwoThousandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_SeniorNotesDueTwoThousandTwentySixMember_01a17858-524b-79e9-8938-038a04f720b0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SeniorNotesDueTwoThousandFortySixMember_01a17858-524b-7b7e-a28c-2a72dc2f0313" xlink:href="xyl-20260930.xsd#xyl_SeniorNotesDueTwoThousandFortySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_SeniorNotesDueTwoThousandFortySixMember_01a17858-524b-7b7e-a28c-2a72dc2f0313" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A3.250SeniorNotesDue2026Member_01a17858-68df-74c5-874f-94601300e68b" xlink:href="xyl-20260930.xsd#xyl_A3.250SeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A3.250SeniorNotesDue2026Member_01a17858-68df-74c5-874f-94601300e68b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A4.375SeniorNotesDue2046Member_01a17858-68df-7be0-8ee5-63ed22b03869" xlink:href="xyl-20260930.xsd#xyl_A4.375SeniorNotesDue2046Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A4.375SeniorNotesDue2046Member_01a17858-68df-7be0-8ee5-63ed22b03869" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_FiveYearRevolvingCreditFacility2023Member_01a17858-802a-7c45-8a47-26fc3b5cb5d2" xlink:href="xyl-20260930.xsd#xyl_FiveYearRevolvingCreditFacility2023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_FiveYearRevolvingCreditFacility2023Member_01a17858-802a-7c45-8a47-26fc3b5cb5d2" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_USDollarCommercialPaperProgramMember_01a17858-b11d-7e0a-bda9-8c22b49d79b6" xlink:href="xyl-20260930.xsd#xyl_USDollarCommercialPaperProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_USDollarCommercialPaperProgramMember_01a17858-b11d-7e0a-bda9-8c22b49d79b6" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_FiveYearRevolvingCreditFacility2019Member_01a17858-b11d-7601-b7c3-856870eca06f" xlink:href="xyl-20260930.xsd#xyl_FiveYearRevolvingCreditFacility2019Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_FiveYearRevolvingCreditFacility2019Member_01a17858-b11d-7601-b7c3-856870eca06f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EuroCommercialPaperProgramMember_01a17858-b11d-7e01-a1c9-54c33a7717de" xlink:href="xyl-20260930.xsd#xyl_EuroCommercialPaperProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_EuroCommercialPaperProgramMember_01a17858-b11d-7e01-a1c9-54c33a7717de" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_A2026CreditFacilityMember_01a1789a-6b75-7a20-8a60-ffdb40825982" xlink:href="xyl-20260930.xsd#xyl_A2026CreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1784f-4658-71d5-a8f1-0419c205f6e4" xlink:to="loc_xyl_A2026CreditFacilityMember_01a1789a-6b75-7a20-8a60-ffdb40825982" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a1784f-4658-7c67-8e6f-53b436ab8c7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a1784f-4658-70f4-ae6b-c32e72dc88d6" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a1784f-4658-7c67-8e6f-53b436ab8c7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7c67-8e6f-53b436ab8c7c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a1784f-4658-7c67-8e6f-53b436ab8c7c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7c67-8e6f-53b436ab8c7c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7d15-b82d-d89c4c3fac5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a1784f-4658-7c67-8e6f-53b436ab8c7c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7d15-b82d-d89c4c3fac5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_01a1784f-4658-7916-9f1c-1fc774a4fbcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7d15-b82d-d89c4c3fac5c" xlink:to="loc_us-gaap_SeniorNotesMember_01a1784f-4658-7916-9f1c-1fc774a4fbcc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_01a17858-802a-77e1-b2f4-b24a3f3252fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a1784f-4658-7d15-b82d-d89c4c3fac5c" xlink:to="loc_us-gaap_LineOfCreditMember_01a17858-802a-77e1-b2f4-b24a3f3252fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_01a17858-802a-7204-8222-5fb2ae2d106f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a1784f-4658-70f4-ae6b-c32e72dc88d6" xlink:to="loc_us-gaap_CreditFacilityAxis_01a17858-802a-7204-8222-5fb2ae2d106f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a17858-802a-7204-8222-5fb2ae2d106f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_01a17858-802a-7204-8222-5fb2ae2d106f" xlink:to="loc_us-gaap_CreditFacilityDomain_01a17858-802a-7204-8222-5fb2ae2d106f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a17858-802a-7639-bdff-026578d3e591" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_01a17858-802a-7204-8222-5fb2ae2d106f" xlink:to="loc_us-gaap_CreditFacilityDomain_01a17858-802a-7639-bdff-026578d3e591" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_01a17858-802a-7fe2-b0c9-1062d683155e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a17858-802a-7639-bdff-026578d3e591" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_01a17858-802a-7fe2-b0c9-1062d683155e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a1784f-4658-79e7-bfdc-3f7dacc9e731" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a1784f-4658-79e7-bfdc-3f7dacc9e731" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a1784f-4658-7a44-b74d-3e6e473b550b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a1784f-4658-7a44-b74d-3e6e473b550b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a17858-3315-7719-ac4a-6f1c3ac0624d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a17858-3315-7719-ac4a-6f1c3ac0624d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DebtInstrumentRedemptionPricePercentageInOccurrenceOfTriggeringEvent_01a17858-524b-79a8-9956-c7d032a38d69" xlink:href="xyl-20260930.xsd#xyl_DebtInstrumentRedemptionPricePercentageInOccurrenceOfTriggeringEvent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_xyl_DebtInstrumentRedemptionPricePercentageInOccurrenceOfTriggeringEvent_01a17858-524b-79a8-9956-c7d032a38d69" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_01a17858-802a-796c-b0ca-abf9e1029d3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_DebtInstrumentTerm_01a17858-802a-796c-b0ca-abf9e1029d3f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a17858-802a-775d-8a12-53fc229b1beb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a17858-802a-775d-8a12-53fc229b1beb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacity_01a17858-802a-7060-a4bd-a56ba9a5762c" xlink:href="xyl-20260930.xsd#xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacity_01a17858-802a-7060-a4bd-a56ba9a5762c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacityTotal_01a17858-802a-736c-ad8b-9b96751608ec" xlink:href="xyl-20260930.xsd#xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacityTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_xyl_LineofCreditFacilityIncreasesinMaximumBorrowingCapacityTotal_01a17858-802a-736c-ad8b-9b96751608ec" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersAfterMaterialAcquisition_01a17858-96d5-77c5-bc9a-42c695b87b29" xlink:href="xyl-20260930.xsd#xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersAfterMaterialAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersAfterMaterialAcquisition_01a17858-96d5-77c5-bc9a-42c695b87b29" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersBeforeAdditionalMaterialAcquisition_01a17858-96d5-75dc-9873-c981242c585a" xlink:href="xyl-20260930.xsd#xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersBeforeAdditionalMaterialAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_xyl_DebtInstrumentCovenantMaximumLeverageRatioFourConsecutiveQuartersBeforeAdditionalMaterialAcquisition_01a17858-96d5-75dc-9873-c981242c585a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_01a17858-96d5-76bf-a4a4-d4e5e133b2fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a1784f-4658-7b18-a50e-3ddeb6eea125" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_01a17858-96d5-76bf-a4a4-d4e5e133b2fd" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellUSDBuyEURMember_01a0d4e9-cdba-7d0c-8342-a133c0ac383f" xlink:href="xyl-20260930.xsd#xyl_SellUSDBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellUSDBuyEURMember_01a0d4e9-cdba-7d0c-8342-a133c0ac383f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellSEKBuyEuroMember_01a0d4e9-cdba-7229-829d-8e557433caf5" xlink:href="xyl-20260930.xsd#xyl_SellSEKBuyEuroMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellSEKBuyEuroMember_01a0d4e9-cdba-7229-829d-8e557433caf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellGBPBuyEURMember_01a0d4e9-cdba-760b-b40c-dc264ec9fb7a" xlink:href="xyl-20260930.xsd#xyl_SellGBPBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellGBPBuyEURMember_01a0d4e9-cdba-760b-b40c-dc264ec9fb7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellCADBuyEURMember_01a0d4e9-cdba-79c5-9ae6-c52678d1128e" xlink:href="xyl-20260930.xsd#xyl_SellCADBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellCADBuyEURMember_01a0d4e9-cdba-79c5-9ae6-c52678d1128e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellCADBuyUSDMember_01a0d4e9-cdba-7e86-8753-7b6ec8fa3d02" xlink:href="xyl-20260930.xsd#xyl_SellCADBuyUSDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellCADBuyUSDMember_01a0d4e9-cdba-7e86-8753-7b6ec8fa3d02" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellPLNBuyEURMember_01a0d4e9-cdba-71c2-b6b3-748118bfecc4" xlink:href="xyl-20260930.xsd#xyl_SellPLNBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellPLNBuyEURMember_01a0d4e9-cdba-71c2-b6b3-748118bfecc4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellAUDBuyEURMember_01a0d4e9-cdba-7aa5-8d70-f22855f7bc89" xlink:href="xyl-20260930.xsd#xyl_SellAUDBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellAUDBuyEURMember_01a0d4e9-cdba-7aa5-8d70-f22855f7bc89" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a0d4e9-cdba-7a73-a3b7-5a72471d0138" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a0d4e9-cdba-7a73-a3b7-5a72471d0138" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:to="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-7bb8-a6da-3bc67117a75b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-7bb8-a6da-3bc67117a75b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-4184-76d9-b9af-23fc59bcbfa1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-4184-76d9-b9af-23fc59bcbfa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_01a15610-4184-7632-a247-057207fd6b07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_01a15610-4184-7632-a247-057207fd6b07" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_01a0d4e9-cdba-7649-a747-d85cd1e7dfe9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_DerivativeNotionalAmount_01a0d4e9-cdba-7649-a747-d85cd1e7dfe9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-4184-72bc-95dc-5f6b785083f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-4184-72bc-95dc-5f6b785083f5" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails_1" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails_1"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsFairValueofForeignExchangeContractsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a0d4e9-cdba-7b95-9e93-302f3b5c1f88" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellUSDBuyEURMember_01a0d4e9-cdba-7d0c-8342-a133c0ac383f" xlink:href="xyl-20260930.xsd#xyl_SellUSDBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellUSDBuyEURMember_01a0d4e9-cdba-7d0c-8342-a133c0ac383f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellSEKBuyEuroMember_01a0d4e9-cdba-7229-829d-8e557433caf5" xlink:href="xyl-20260930.xsd#xyl_SellSEKBuyEuroMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellSEKBuyEuroMember_01a0d4e9-cdba-7229-829d-8e557433caf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellGBPBuyEURMember_01a0d4e9-cdba-760b-b40c-dc264ec9fb7a" xlink:href="xyl-20260930.xsd#xyl_SellGBPBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellGBPBuyEURMember_01a0d4e9-cdba-760b-b40c-dc264ec9fb7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellCADBuyEURMember_01a0d4e9-cdba-79c5-9ae6-c52678d1128e" xlink:href="xyl-20260930.xsd#xyl_SellCADBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellCADBuyEURMember_01a0d4e9-cdba-79c5-9ae6-c52678d1128e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellCADBuyUSDMember_01a0d4e9-cdba-7e86-8753-7b6ec8fa3d02" xlink:href="xyl-20260930.xsd#xyl_SellCADBuyUSDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellCADBuyUSDMember_01a0d4e9-cdba-7e86-8753-7b6ec8fa3d02" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellPLNBuyEURMember_01a0d4e9-cdba-71c2-b6b3-748118bfecc4" xlink:href="xyl-20260930.xsd#xyl_SellPLNBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellPLNBuyEURMember_01a0d4e9-cdba-71c2-b6b3-748118bfecc4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SellAUDBuyEURMember_01a0d4e9-cdba-7aa5-8d70-f22855f7bc89" xlink:href="xyl-20260930.xsd#xyl_SellAUDBuyEURMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_xyl_SellAUDBuyEURMember_01a0d4e9-cdba-7aa5-8d70-f22855f7bc89" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a0d4e9-cdba-7a73-a3b7-5a72471d0138" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a0d4e9-cdba-754a-b41f-4dc5f7e04e23" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a0d4e9-cdba-7a73-a3b7-5a72471d0138" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fb94e-de32-74ff-ad5f-11e66f0e2d9f" xlink:to="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-7bb8-a6da-3bc67117a75b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-7bb8-a6da-3bc67117a75b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-4184-7bb8-a6da-3bc67117a75b" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-4184-76d9-b9af-23fc59bcbfa1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_01a15610-4184-732e-99e6-3d8e6f5ffe99" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-4184-76d9-b9af-23fc59bcbfa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_01a0d4e9-cdba-7649-a747-d85cd1e7dfe9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_DerivativeNotionalAmount_01a0d4e9-cdba-7649-a747-d85cd1e7dfe9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-4184-72bc-95dc-5f6b785083f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fb94e-de32-7fac-ba84-a3cfe96eab61" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-4184-72bc-95dc-5f6b785083f5" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_01a15609-5b6d-7eaf-8eb4-ae0525591fed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_01a15609-5b6d-7121-937c-10af25868b70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_01a15609-5b6d-7eaf-8eb4-ae0525591fed" xlink:to="loc_us-gaap_DerivativeTable_01a15609-5b6d-7121-937c-10af25868b70" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15609-5b6d-7121-937c-10af25868b70" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-78e2-beb1-460f642778f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a15609-5b6d-7b5d-9d0e-7fa0b411ed96" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-78e2-beb1-460f642778f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a15609-5b6d-7436-a028-fc4060ca5237" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-78e2-beb1-460f642778f0" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a15609-5b6d-7436-a028-fc4060ca5237" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a15609-71a9-7747-bffd-f1b4f86edfe4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-78e2-beb1-460f642778f0" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a15609-71a9-7747-bffd-f1b4f86edfe4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_01a1560a-83a3-7921-88ff-bb7aebdecd49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a15609-5b6d-78e2-beb1-460f642778f0" xlink:to="loc_us-gaap_InterestRateSwapMember_01a1560a-83a3-7921-88ff-bb7aebdecd49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_01a15609-71a9-7d37-887a-0fc829bf5768" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15609-5b6d-7121-937c-10af25868b70" xlink:to="loc_us-gaap_HedgingDesignationAxis_01a15609-71a9-7d37-887a-0fc829bf5768" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15609-71a9-7d37-887a-0fc829bf5768_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15609-71a9-7d37-887a-0fc829bf5768" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15609-71a9-7d37-887a-0fc829bf5768_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15609-71a9-7c4d-86ea-113e61bc66b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15609-71a9-7d37-887a-0fc829bf5768" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15609-71a9-7c4d-86ea-113e61bc66b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15609-71a9-7c2d-8ced-0b9da26c1b80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_01a15609-71a9-7c4d-86ea-113e61bc66b3" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15609-71a9-7c2d-8ced-0b9da26c1b80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_01a15609-5b6d-7170-9bd0-4054bcf67aef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15609-5b6d-7eaf-8eb4-ae0525591fed" xlink:to="loc_us-gaap_DerivativeNotionalAmount_01a15609-5b6d-7170-9bd0-4054bcf67aef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeGainLossToBeReclassifiedDuringNext12Months_01a15609-8e60-7d58-b822-21387f88cd10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeGainLossToBeReclassifiedDuringNext12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15609-5b6d-7eaf-8eb4-ae0525591fed" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeGainLossToBeReclassifiedDuringNext12Months_01a15609-8e60-7d58-b822-21387f88cd10" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsOCIDerivativeChangesDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsOCIDerivativeChangesDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsOCIDerivativeChangesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-704f-bf5a-97383489bf71_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-704f-bf5a-97383489bf71_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a1560d-8395-74e5-84bd-e1afe27b5fa1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a1560d-8395-74e5-84bd-e1afe27b5fa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a1560e-c789-743f-9188-b605a11e0d31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a1560e-c789-743f-9188-b605a11e0d31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_01a1560d-db5b-7e82-b189-d32bbae2cb32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_01a1560d-db5b-7e82-b189-d32bbae2cb32" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_01a1560f-e995-7c82-881e-3f47004284ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_01a1560f-e995-7c82-881e-3f47004284ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_01a1560d-8395-7d75-bab7-4cc943cdbd47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_01a1560d-8395-7d75-bab7-4cc943cdbd47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax_01a1560e-99a0-758e-b777-ec229fa315dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax_01a1560e-99a0-758e-b777-ec229fa315dc" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsOCIDerivativeChangesDetails_1" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsOCIDerivativeChangesDetails_1"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsOCIDerivativeChangesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a1560d-8395-79ea-b33b-33b1a8253577" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-704f-bf5a-97383489bf71_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-704f-bf5a-97383489bf71_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a1560d-8395-704f-bf5a-97383489bf71" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a1560d-8395-74e5-84bd-e1afe27b5fa1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a1560d-8395-74e5-84bd-e1afe27b5fa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a1560e-c789-743f-9188-b605a11e0d31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a1560d-8395-7881-a946-f54c70c394fc" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_01a1560e-c789-743f-9188-b605a11e0d31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_01a1560f-e995-7c82-881e-3f47004284ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_01a1560f-e995-7c82-881e-3f47004284ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_01a1560d-8395-7d75-bab7-4cc943cdbd47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_01a1560d-8395-7d75-bab7-4cc943cdbd47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax_01a1560e-99a0-758e-b777-ec229fa315dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a1560d-8395-77cc-990f-fe89d2b6bed6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax_01a1560e-99a0-758e-b777-ec229fa315dc" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:to="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-6b5b-796f-8ccc-9e89a8332a92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-6b5b-796f-8ccc-9e89a8332a92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_01a15610-6b5b-763f-ac6f-11c42ae1a5c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_01a15610-6b5b-763f-ac6f-11c42ae1a5c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-7cb4-9db6-4b7be324e69b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-7cb4-9db6-4b7be324e69b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_01a15610-6b5b-7c44-a3b5-6405f6952ecb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_CashFlowHedgingMember_01a15610-6b5b-7c44-a3b5-6405f6952ecb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_01a15612-1d3f-7295-ac07-1c1389dbeab7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_01a15612-1d3f-7295-ac07-1c1389dbeab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_01a15611-fb1e-76ac-b832-5bac49291940" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_FairValueHedgingMember_01a15611-fb1e-76ac-b832-5bac49291940" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-6b5b-7237-b197-fa72a11bef77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-6b5b-7237-b197-fa72a11bef77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_01a15610-6b5b-79c9-bedb-d7eccce8771e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_01a15610-6b5b-79c9-bedb-d7eccce8771e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails_1" xlink:type="simple" xlink:href="xyl-20260930.xsd#DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails_1"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/DerivativeFinancialInstrumentsDerivativesDesignatedasHedgingDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:to="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_01a15610-6b5b-7f8a-87bf-e0f2bc1131bf" xlink:to="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-6b5b-796f-8ccc-9e89a8332a92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_01a15610-6b5b-7a31-8f24-078e185d2d71" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_01a15610-6b5b-796f-8ccc-9e89a8332a92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_01a15610-6b5b-770a-8fdc-837fd7a6298d" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-7cb4-9db6-4b7be324e69b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-7cb4-9db6-4b7be324e69b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_01a15610-6b5b-7cb4-9db6-4b7be324e69b" xlink:to="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_01a15610-6b5b-7c44-a3b5-6405f6952ecb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_CashFlowHedgingMember_01a15610-6b5b-7c44-a3b5-6405f6952ecb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_01a15612-1d3f-7295-ac07-1c1389dbeab7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_01a15612-1d3f-7295-ac07-1c1389dbeab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_01a15611-fb1e-76ac-b832-5bac49291940" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_01a15610-6b5b-764c-935e-91c6fa64d450" xlink:to="loc_us-gaap_FairValueHedgingMember_01a15611-fb1e-76ac-b832-5bac49291940" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-6b5b-7237-b197-fa72a11bef77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeAssetAtFairValue_01a15610-6b5b-7237-b197-fa72a11bef77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_01a15610-6b5b-79c9-bedb-d7eccce8771e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_01a15610-6b5b-73ca-be1d-f56265e74712" xlink:to="loc_us-gaap_ForeignCurrencyCashFlowHedgeLiabilityAtFairValue_01a15610-6b5b-79c9-bedb-d7eccce8771e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/PostretirementBenefitPlansComponentsofNetPeriodicBenefitCostDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#PostretirementBenefitPlansComponentsofNetPeriodicBenefitCostDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/PostretirementBenefitPlansComponentsofNetPeriodicBenefitCostDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15617-5400-725c-87ec-f6355a29bd27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15617-5400-725c-87ec-f6355a29bd27" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_01a15617-5400-7645-b238-18cf411fbcec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15617-5400-725c-87ec-f6355a29bd27" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_01a15617-5400-7645-b238-18cf411fbcec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7645-b238-18cf411fbcec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_01a15617-5400-7645-b238-18cf411fbcec" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7645-b238-18cf411fbcec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7d0d-b793-7a9fad55ce2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_01a15617-5400-7645-b238-18cf411fbcec" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7d0d-b793-7a9fad55ce2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_01a178b7-630a-7f95-9b27-b4490492e521" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7d0d-b793-7a9fad55ce2d" xlink:to="loc_us-gaap_DomesticPlanMember_01a178b7-630a-7f95-9b27-b4490492e521" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_01a15617-5400-78c1-93f1-bcd9fa491b74" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_01a178b7-630a-7f95-9b27-b4490492e521" xlink:to="loc_country_US_01a15617-5400-78c1-93f1-bcd9fa491b74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_01a15617-5400-749f-97c5-f396f0a41b50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_01a15617-5400-7d0d-b793-7a9fad55ce2d" xlink:to="loc_us-gaap_ForeignPlanMember_01a15617-5400-749f-97c5-f396f0a41b50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_01a15617-5400-77cb-816b-d0204f889517" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_01a15617-5400-77cb-816b-d0204f889517" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_01a15617-5401-7c29-a0ef-52f49fe8e0ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_01a15617-5401-7c29-a0ef-52f49fe8e0ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_01a15617-5401-749a-b9c9-d727c1af0f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_01a15617-5401-749a-b9c9-d727c1af0f0d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_01a15617-5401-78e1-8c08-c3a060e93cce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_01a15617-5401-78e1-8c08-c3a060e93cce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_01a15617-5401-7818-b5d1-c20faa5bc266" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15617-5400-71ea-9b37-310e3ba1e944" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_01a15617-5401-7818-b5d1-c20faa5bc266" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/PostretirementBenefitPlansNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#PostretirementBenefitPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/PostretirementBenefitPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15619-1cc5-760b-a48a-df6e5946c73d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15619-1cc5-760b-a48a-df6e5946c73d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a15619-1cc5-7265-9379-ed820244d008" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15619-1cc5-760b-a48a-df6e5946c73d" xlink:to="loc_srt_RangeAxis_01a15619-1cc5-7265-9379-ed820244d008" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a15619-1cc5-7265-9379-ed820244d008_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_01a15619-1cc5-7265-9379-ed820244d008" xlink:to="loc_srt_RangeMember_01a15619-1cc5-7265-9379-ed820244d008_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a15619-1cc5-7840-8cd3-e62075b2ccd9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_01a15619-1cc5-7265-9379-ed820244d008" xlink:to="loc_srt_RangeMember_01a15619-1cc5-7840-8cd3-e62075b2ccd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a15619-1cc5-7ebe-a7e8-ad844d028099" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a15619-1cc5-7840-8cd3-e62075b2ccd9" xlink:to="loc_srt_MaximumMember_01a15619-1cc5-7ebe-a7e8-ad844d028099" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a15619-1cc5-714b-b774-916dc5b46439" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a15619-1cc5-7840-8cd3-e62075b2ccd9" xlink:to="loc_srt_MinimumMember_01a15619-1cc5-714b-b774-916dc5b46439" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_01a15619-1cc5-7141-8b22-fd8e5ea7add9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_01a15619-1cc5-760b-a48a-df6e5946c73d" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_01a15619-1cc5-7141-8b22-fd8e5ea7add9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-7141-8b22-fd8e5ea7add9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_01a15619-1cc5-7141-8b22-fd8e5ea7add9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-7141-8b22-fd8e5ea7add9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-79e7-89fe-2b136dc09afd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_01a15619-1cc5-7141-8b22-fd8e5ea7add9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-79e7-89fe-2b136dc09afd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_01a15619-1cc5-7f4a-8817-fcd5dfb888b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-79e7-89fe-2b136dc09afd" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_01a15619-1cc5-7f4a-8817-fcd5dfb888b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_01a15619-1cc5-73d0-8039-194eb57829e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_01a15619-1cc5-79e7-89fe-2b136dc09afd" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_01a15619-1cc5-73d0-8039-194eb57829e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_01a15619-1cc5-7d80-a9e3-385c878003bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_01a15619-1cc5-7d80-a9e3-385c878003bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_01a15619-1cc5-7321-8a4a-e00414bf5538" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_01a15619-1cc5-7321-8a4a-e00414bf5538" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_01a15619-1cc5-7050-be7f-09505f829d12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_01a15619-1cc5-7050-be7f-09505f829d12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitExpense_01a1785b-4384-79dc-b79c-fc2e82cf54d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherPostretirementBenefitExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01a15619-1cc5-7635-b3be-6b32fdf429b5" xlink:to="loc_us-gaap_OtherPostretirementBenefitExpense_01a1785b-4384-79dc-b79c-fc2e82cf54d2" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/EquityDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#EquityDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/EquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EquityLineItems_01a1785d-55c2-7e44-bb4d-f859b675779d" xlink:href="xyl-20260930.xsd#xyl_EquityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EquityTable_01a1785d-55c2-70cf-beaa-5a57f4b33ec5" xlink:href="xyl-20260930.xsd#xyl_EquityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_xyl_EquityLineItems_01a1785d-55c2-7e44-bb4d-f859b675779d" xlink:to="loc_xyl_EquityTable_01a1785d-55c2-70cf-beaa-5a57f4b33ec5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_01a1785d-55c2-7f80-89e4-6bf3e432b80b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_xyl_EquityTable_01a1785d-55c2-70cf-beaa-5a57f4b33ec5" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_01a1785d-55c2-7f80-89e4-6bf3e432b80b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-7f80-89e4-6bf3e432b80b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_01a1785d-55c2-7f80-89e4-6bf3e432b80b" xlink:to="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-7f80-89e4-6bf3e432b80b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_01a1785d-55c2-7f80-89e4-6bf3e432b80b" xlink:to="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_01a1785d-55c2-7c2f-8164-ecff91301de6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_CommonStockMember_01a1785d-55c2-7c2f-8164-ecff91301de6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_01a1785d-55c2-7eac-bc3c-004269256438" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_01a1785d-55c2-7eac-bc3c-004269256438" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_01a1785d-55c2-7d3b-b9bd-bfab189c8b21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_RetainedEarningsMember_01a1785d-55c2-7d3b-b9bd-bfab189c8b21" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a1785d-55c2-7440-ae9d-e527e8fa7e72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a1785d-55c2-7440-ae9d-e527e8fa7e72" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_01a1785d-55c2-7152-aaa1-7b2386484192" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_TreasuryStockCommonMember_01a1785d-55c2-7152-aaa1-7b2386484192" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_01a1785d-55c2-7873-9cb7-64781fd6e103" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a1785d-55c2-79c9-b2c8-2d0b3b1ddb33" xlink:to="loc_us-gaap_NoncontrollingInterestMember_01a1785d-55c2-7873-9cb7-64781fd6e103" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_xyl_EquityLineItems_01a1785d-55c2-7e44-bb4d-f859b675779d" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_01a1785d-55c2-7057-959b-664e7bdd826d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_01a1785d-55c2-7057-959b-664e7bdd826d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a1785d-55c2-7abb-93ed-e0a20b763df8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_NetIncomeLoss_01a1785d-55c2-7abb-93ed-e0a20b763df8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a178c7-01fb-7bd4-9fc8-100762fd4d17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a178c7-01fb-7bd4-9fc8-100762fd4d17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation_01a1785d-55c2-7018-86ef-1c9e6b9e6b30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_NoncontrollingInterestDecreaseFromDeconsolidation_01a1785d-55c2-7018-86ef-1c9e6b9e6b30" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_01a1785d-55c2-7423-9179-78a942f18d2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_StockholdersEquityOther_01a1785d-55c2-7423-9179-78a942f18d2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_01a1785d-55c2-71cb-8694-7d965d48ff92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_DividendsCash_01a1785d-55c2-71cb-8694-7d965d48ff92" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_01a1785d-55c2-76d2-9636-388f50034ec1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_01a1785d-55c2-76d2-9636-388f50034ec1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_01a1785d-55c2-75d1-b5fb-1911ecd0f0a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNonredeemableNoncontrollingInterest_01a1785d-55c2-75d1-b5fb-1911ecd0f0a3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a1785d-55c2-748d-9927-44ff9bfa12bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a1785d-55c2-748d-9927-44ff9bfa12bb" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a1785d-55c2-7491-b270-5e9c90f721b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a1785d-55c2-7292-ad87-d3c3e0961f0a" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a1785d-55c2-7491-b270-5e9c90f721b8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_01a1785d-55c2-7e6b-b86d-33c1c8a3a3dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_01a1785d-55c2-7199-a959-e574276dcc08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_xyl_EquityLineItems_01a1785d-55c2-7e44-bb4d-f859b675779d" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_01a1785d-55c2-7199-a959-e574276dcc08" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/ShareBasedCompensationPlansNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#ShareBasedCompensationPlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ShareBasedCompensationPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a17863-65cf-7a4f-90e1-5dfe4ca819da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a17863-65cf-7a4f-90e1-5dfe4ca819da" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a17863-65cf-7e9b-a235-1eb46c6ba5c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a17863-65cf-7a4f-90e1-5dfe4ca819da" xlink:to="loc_us-gaap_AwardTypeAxis_01a17863-65cf-7e9b-a235-1eb46c6ba5c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7e9b-a235-1eb46c6ba5c3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a17863-65cf-7e9b-a235-1eb46c6ba5c3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7e9b-a235-1eb46c6ba5c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a17863-65cf-7e9b-a235-1eb46c6ba5c3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_01a17863-65cf-71f8-8048-c3de4303b0c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_01a17863-65cf-71f8-8048-c3de4303b0c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_01a17863-65cf-7866-b020-bd1c908eb7e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_01a17863-65cf-7866-b020-bd1c908eb7e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_01a17863-65cf-74f3-929f-ec487bdf7a18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:to="loc_us-gaap_PerformanceSharesMember_01a17863-65cf-74f3-929f-ec487bdf7a18" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01a17863-eb73-703b-9216-113d016567aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:to="loc_us-gaap_RestrictedStockMember_01a17863-eb73-703b-9216-113d016567aa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_01a17865-4338-7a3a-a19b-c17676056849" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a17863-65cf-7add-99b1-1e1afee8679d" xlink:to="loc_us-gaap_EmployeeStockMember_01a17865-4338-7a3a-a19b-c17676056849" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a17863-65cf-7b12-8a96-85f174211a08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a17863-65cf-7b12-8a96-85f174211a08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_01a17863-65cf-72e0-8fd4-e6bcb7acf200" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_01a17863-65cf-72e0-8fd4-e6bcb7acf200" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01a17863-65cf-7c4b-97c2-2d058a53ceb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01a17863-65cf-7c4b-97c2-2d058a53ceb8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_01a17863-65cf-7c00-bd02-1c5e90e61507" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_01a17863-65cf-7c00-bd02-1c5e90e61507" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a17863-65cf-766e-8703-eb745cc81906" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a17863-65cf-766e-8703-eb745cc81906" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_01a17863-d961-7189-90ed-4a1f4c326424" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_01a17863-d961-7189-90ed-4a1f4c326424" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_01a17863-eb73-7cac-969a-5b8d4d9cccea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_01a17863-eb73-7cac-969a-5b8d4d9cccea" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPayoutPercentage_01a17864-028c-763b-b59d-acfc93684bba" xlink:href="xyl-20260930.xsd#xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPayoutPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPayoutPercentage_01a17864-028c-763b-b59d-acfc93684bba" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfEPSPerformanceTarget_01a17864-028c-7d0e-a13f-049cdd004be7" xlink:href="xyl-20260930.xsd#xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfEPSPerformanceTarget"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfEPSPerformanceTarget_01a17864-028c-7d0e-a13f-049cdd004be7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfAdjustedEBITDAPerformanceTarget_01a17864-c6d7-7a9c-8e39-ced39eab7ec0" xlink:href="xyl-20260930.xsd#xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfAdjustedEBITDAPerformanceTarget"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfAdjustedEBITDAPerformanceTarget_01a17864-c6d7-7a9c-8e39-ced39eab7ec0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfRevenuePerformanceTarget_01a17864-e4ec-70d6-aae9-4d9425996072" xlink:href="xyl-20260930.xsd#xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfRevenuePerformanceTarget"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_xyl_ShareBasedCompensationArrangementByShareBasedPaymentAwardRevenuePerformanceShareUnitGrantTermOfRevenuePerformanceTarget_01a17864-e4ec-70d6-aae9-4d9425996072" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_01a17865-4338-7c21-bbbe-67df7e79ef82" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_01a17865-4338-7c21-bbbe-67df7e79ef82" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_01a17865-6842-7aba-87c8-19aae6232ce7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_01a17865-6842-7aba-87c8-19aae6232ce7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a17865-88a3-71f2-a4ea-0f2fcf987cdc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a17863-65cf-7d72-a569-5b4547669b99" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a17865-88a3-71f2-a4ea-0f2fcf987cdc" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/ShareBasedCompensationPlansRestrictedStockUnitActivityDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#ShareBasedCompensationPlansRestrictedStockUnitActivityDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ShareBasedCompensationPlansRestrictedStockUnitActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-72d0-b2c9-6844a79b182a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7550-9fab-138092694f1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-72d0-b2c9-6844a79b182a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7550-9fab-138092694f1c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019fb94e-de33-73c9-aad4-b78949da596d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7550-9fab-138092694f1c" xlink:to="loc_us-gaap_AwardTypeAxis_019fb94e-de33-73c9-aad4-b78949da596d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-73c9-aad4-b78949da596d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-73c9-aad4-b78949da596d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-73c9-aad4-b78949da596d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79a6-987e-5239a70b8134" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-73c9-aad4-b78949da596d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79a6-987e-5239a70b8134" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019fb94e-de33-774e-973d-5e2203188c0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79a6-987e-5239a70b8134" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019fb94e-de33-774e-973d-5e2203188c0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-72d0-b2c9-6844a79b182a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-7c50-ad91-d584b350347c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-7c50-ad91-d584b350347c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-7938-a908-ef1799ad2332" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-7938-a908-ef1799ad2332" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-74c4-8caa-e8b28411d23c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-74c4-8caa-e8b28411d23c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-721b-9c51-bd446b38a6c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-70fd-8b11-4870c996d8c2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-721b-9c51-bd446b38a6c7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-7d2c-97f2-6cf2c5ce07f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-72d0-b2c9-6844a79b182a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-71aa-aa64-3b3a64038cdd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-71aa-aa64-3b3a64038cdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-7619-a41e-67c5c5d61e07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-7619-a41e-67c5c5d61e07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-775f-8b66-be7f633ffc59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-775f-8b66-be7f633ffc59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-74f9-9949-90b6cd699e59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7a1f-99e2-c763228a7a02" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-74f9-9949-90b6cd699e59" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-7dca-b25c-edf805b4324d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/ShareBasedCompensationPlansPerformanceShareActivityDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#ShareBasedCompensationPlansPerformanceShareActivityDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ShareBasedCompensationPlansPerformanceShareActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7a52-84d9-cef7bf0700e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7a52-84d9-cef7bf0700e3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019fb94e-de33-75c9-9a9b-2657953441b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7a52-84d9-cef7bf0700e3" xlink:to="loc_us-gaap_PlanNameAxis_019fb94e-de33-75c9-9a9b-2657953441b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-75c9-9a9b-2657953441b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-75c9-9a9b-2657953441b4" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-75c9-9a9b-2657953441b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-75c9-9a9b-2657953441b4" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ReturnonInvestedCapitalPerformanceBasedSharesMember_019fb94e-de33-786a-a6cb-47d4c01d0ed5" xlink:href="xyl-20260930.xsd#xyl_ReturnonInvestedCapitalPerformanceBasedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:to="loc_xyl_ReturnonInvestedCapitalPerformanceBasedSharesMember_019fb94e-de33-786a-a6cb-47d4c01d0ed5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RevenuePerformanceSharesMember_019fb94e-de33-7959-bdfa-2447118404b5" xlink:href="xyl-20260930.xsd#xyl_RevenuePerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:to="loc_xyl_RevenuePerformanceSharesMember_019fb94e-de33-7959-bdfa-2447118404b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TotalShareholderReturnPerformanceBasedSharesMember_019fb94e-de33-7c6c-8e53-48002a3eb7d8" xlink:href="xyl-20260930.xsd#xyl_TotalShareholderReturnPerformanceBasedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:to="loc_xyl_TotalShareholderReturnPerformanceBasedSharesMember_019fb94e-de33-7c6c-8e53-48002a3eb7d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EPSPerformanceShareMember_019fb94e-de33-7b4f-99f3-319cfeebf466" xlink:href="xyl-20260930.xsd#xyl_EPSPerformanceShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-7d16-8e0a-e33c4d3adf58" xlink:to="loc_xyl_EPSPerformanceShareMember_019fb94e-de33-7b4f-99f3-319cfeebf466" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7393-a156-01c9a190bea8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7a52-84d9-cef7bf0700e3" xlink:to="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7393-a156-01c9a190bea8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7393-a156-01c9a190bea8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7393-a156-01c9a190bea8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7393-a156-01c9a190bea8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79f6-b3ed-594a5bebedcf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7393-a156-01c9a190bea8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79f6-b3ed-594a5bebedcf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-797b-8553-34cbe37702e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-79f6-b3ed-594a5bebedcf" xlink:to="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-797b-8553-34cbe37702e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-701b-8954-96cc9264f6c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-701b-8954-96cc9264f6c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-7808-ab42-dba3114bf015" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-7808-ab42-dba3114bf015" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-7340-b72c-50d4ea050871" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-7340-b72c-50d4ea050871" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-7220-ad3d-9846a16ad23b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7f1e-b04e-6974df3f976d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-7220-ad3d-9846a16ad23b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019fb94e-de33-73ae-ac66-8eb678653109" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-7914-a44b-9043b1ec9ade" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-7914-a44b-9043b1ec9ade" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-73aa-b1a4-61c05c7cc91c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-73aa-b1a4-61c05c7cc91c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-744b-9d02-f77036dcefa7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-744b-9d02-f77036dcefa7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-7bb0-8e97-3861a891fd72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7140-9251-5600b4bbbc20" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-7bb0-8e97-3861a891fd72" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-7df0-88d4-9c48a0460ee2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod_019fb94e-de33-71e0-a5c6-2dbf2187fd38" xlink:href="xyl-20260930.xsd#xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod_019fb94e-de33-71e0-a5c6-2dbf2187fd38" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-73bd-8148-15a28d9831d3" xlink:href="xyl-20260930.xsd#xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-73bd-8148-15a28d9831d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019fb94e-de33-7b0c-8e74-6ea883398e2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7f5c-958c-7e36b7d95d7c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019fb94e-de33-7b0c-8e74-6ea883398e2a" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/ShareBasedCompensationPlansTSRFairValueAssumptionsDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#ShareBasedCompensationPlansTSRFairValueAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ShareBasedCompensationPlansTSRFairValueAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-77f3-9fbd-2583a28b91ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7cc6-92b2-095e0f54582a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-77f3-9fbd-2583a28b91ab" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7cc6-92b2-095e0f54582a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019fb94e-de33-73d4-8821-87ebf0dae5ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7cc6-92b2-095e0f54582a" xlink:to="loc_us-gaap_PlanNameAxis_019fb94e-de33-73d4-8821-87ebf0dae5ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-73d4-8821-87ebf0dae5ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-73d4-8821-87ebf0dae5ab" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-73d4-8821-87ebf0dae5ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-775a-81fc-d9e06a45feb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-73d4-8821-87ebf0dae5ab" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-775a-81fc-d9e06a45feb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TotalShareholderReturnPerformanceBasedSharesMember_019fb94e-de33-7a42-86ea-3887dd0255a2" xlink:href="xyl-20260930.xsd#xyl_TotalShareholderReturnPerformanceBasedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-775a-81fc-d9e06a45feb5" xlink:to="loc_xyl_TotalShareholderReturnPerformanceBasedSharesMember_019fb94e-de33-7a42-86ea-3887dd0255a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019fb94e-de33-791c-a858-4ffc40182d86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7cc6-92b2-095e0f54582a" xlink:to="loc_us-gaap_AwardTypeAxis_019fb94e-de33-791c-a858-4ffc40182d86" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-791c-a858-4ffc40182d86_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-791c-a858-4ffc40182d86" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-791c-a858-4ffc40182d86_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7a5d-9346-30d82d98d94a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-791c-a858-4ffc40182d86" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7a5d-9346-30d82d98d94a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-7696-bf15-f56283ff3bc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7a5d-9346-30d82d98d94a" xlink:to="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-7696-bf15-f56283ff3bc7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019fb94e-de33-7e20-a950-8d0cb4100049" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-77f3-9fbd-2583a28b91ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019fb94e-de33-7e20-a950-8d0cb4100049" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019fb94e-de33-7478-a3a2-47a08c68eb03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-77f3-9fbd-2583a28b91ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019fb94e-de33-7478-a3a2-47a08c68eb03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019fb94e-de33-7783-8b2a-4e7579daa8ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-77f3-9fbd-2583a28b91ab" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019fb94e-de33-7783-8b2a-4e7579daa8ff" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/ShareBasedCompensationPlansRevenuePerformanceShareUnitsDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#ShareBasedCompensationPlansRevenuePerformanceShareUnitsDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/ShareBasedCompensationPlansRevenuePerformanceShareUnitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7fa4-b58d-9b9fdbf3c126" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7fa4-b58d-9b9fdbf3c126" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7aff-b584-96e963c7178b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7fa4-b58d-9b9fdbf3c126" xlink:to="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7aff-b584-96e963c7178b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7aff-b584-96e963c7178b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7aff-b584-96e963c7178b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7aff-b584-96e963c7178b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7b80-9ac8-530200a88211" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019fb94e-de33-7aff-b584-96e963c7178b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7b80-9ac8-530200a88211" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-7d19-b607-f1ad7d565cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019fb94e-de33-7b80-9ac8-530200a88211" xlink:to="loc_us-gaap_PerformanceSharesMember_019fb94e-de33-7d19-b607-f1ad7d565cbd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019fb94e-de33-7611-8da8-5518ce8a2373" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019fb94e-de33-7fa4-b58d-9b9fdbf3c126" xlink:to="loc_us-gaap_PlanNameAxis_019fb94e-de33-7611-8da8-5518ce8a2373" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-7611-8da8-5518ce8a2373_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-7611-8da8-5518ce8a2373" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-7611-8da8-5518ce8a2373_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019fb94e-de33-785b-a2e1-c521ae406b91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019fb94e-de33-7611-8da8-5518ce8a2373" xlink:to="loc_us-gaap_PlanNameDomain_019fb94e-de33-785b-a2e1-c521ae406b91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RevenuePerformanceSharesMember_019fb94e-de33-7b14-a28b-01f111caf910" xlink:href="xyl-20260930.xsd#xyl_RevenuePerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019fb94e-de33-785b-a2e1-c521ae406b91" xlink:to="loc_xyl_RevenuePerformanceSharesMember_019fb94e-de33-7b14-a28b-01f111caf910" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7906-bf75-e18ca17c89b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7906-bf75-e18ca17c89b5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019fb94e-de33-74ac-b1c1-b758eeba717c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7906-bf75-e18ca17c89b5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019fb94e-de33-74ac-b1c1-b758eeba717c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-71a8-8240-8fc76c89f42a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7906-bf75-e18ca17c89b5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019fb94e-de33-71a8-8240-8fc76c89f42a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-7c7b-a665-a25666872a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019fb94e-de33-7906-bf75-e18ca17c89b5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019fb94e-de33-7c7b-a665-a25666872a5b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_019fb94e-de33-7a39-a86b-18d649eae739" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7fec-95ce-8bfb961bc57c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7fec-95ce-8bfb961bc57c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-70f3-b604-5ccb1428fd72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7fec-95ce-8bfb961bc57c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-70f3-b604-5ccb1428fd72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-772a-aec6-8e738565a5bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7fec-95ce-8bfb961bc57c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-772a-aec6-8e738565a5bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-7ab3-8d1c-1e9c73a0ddfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019fb94e-de33-7fec-95ce-8bfb961bc57c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019fb94e-de33-7ab3-8d1c-1e9c73a0ddfe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019fb94e-de33-7621-8efe-94712f6fc874" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod_019fb94e-de33-7cc3-9042-3a7db2af9a57" xlink:href="xyl-20260930.xsd#xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriod_019fb94e-de33-7cc3-9042-3a7db2af9a57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-7499-b49a-f3b0f32b9b3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019fb94e-de33-7499-b49a-f3b0f32b9b3c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-7733-9668-23d72c160b29" xlink:href="xyl-20260930.xsd#xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_xyl_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentsInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-7733-9668-23d72c160b29" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-72d0-9e4a-145b076a4306" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019fb94e-de33-7dac-b6d1-f5c846b0a6bd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019fb94e-de33-72d0-9e4a-145b076a4306" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/CapitalStockDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#CapitalStockDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/CapitalStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_01a17868-03e2-7aa8-9188-40d8c6bd4040" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_01a17868-03e2-7aa8-9188-40d8c6bd4040" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_01a17868-03e2-7b8b-b341-b3093ab1b6e0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_01a17868-03e2-7aa8-9188-40d8c6bd4040" xlink:to="loc_srt_ShareRepurchaseProgramAxis_01a17868-03e2-7b8b-b341-b3093ab1b6e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7b8b-b341-b3093ab1b6e0_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a17868-03e2-7b8b-b341-b3093ab1b6e0" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7b8b-b341-b3093ab1b6e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a17868-03e2-7b8b-b341-b3093ab1b6e0" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_ShareRepurchasePlansMember_01a17868-03e2-71ef-bba4-9d1b4c08a66c" xlink:href="xyl-20260930.xsd#xyl_ShareRepurchasePlansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:to="loc_xyl_ShareRepurchasePlansMember_01a17868-03e2-71ef-bba4-9d1b4c08a66c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TwoThousandfifteenStockRepurchaseProgramMember_01a17868-03e2-7ab2-a220-c079f4779c6f" xlink:href="xyl-20260930.xsd#xyl_TwoThousandfifteenStockRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:to="loc_xyl_TwoThousandfifteenStockRepurchaseProgramMember_01a17868-03e2-7ab2-a220-c079f4779c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_February2026ProgramMember_01a17868-03e2-7fc8-ac37-738cb9932dbd" xlink:href="xyl-20260930.xsd#xyl_February2026ProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:to="loc_xyl_February2026ProgramMember_01a17868-03e2-7fc8-ac37-738cb9932dbd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_SettlementofEmployeeTaxWithholdingObligationsMember_01a17868-03e2-7b79-98fe-db8b92b92da7" xlink:href="xyl-20260930.xsd#xyl_SettlementofEmployeeTaxWithholdingObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a17868-03e2-7f74-bf21-b3fdd48bb08a" xlink:to="loc_xyl_SettlementofEmployeeTaxWithholdingObligationsMember_01a17868-03e2-7b79-98fe-db8b92b92da7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_01a17868-03e2-7c7b-8bce-a2b1d56012b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_01a17868-03e2-7c7b-8bce-a2b1d56012b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a17868-03e2-7012-a6c6-0dd322b77159" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a17868-03e2-7012-a6c6-0dd322b77159" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a17868-03e2-77e9-8991-a9015780a4ec" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a17868-03e2-77e9-8991-a9015780a4ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_01a17868-03e2-7fc7-841c-b61a0d656255" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_01a17868-03e2-7fc7-841c-b61a0d656255" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_TreasuryStockValueAcquiredAccruedExciseTaxes_01a17868-03e2-7c27-bd3e-98e5dd3277ba" xlink:href="xyl-20260930.xsd#xyl_TreasuryStockValueAcquiredAccruedExciseTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_xyl_TreasuryStockValueAcquiredAccruedExciseTaxes_01a17868-03e2-7c27-bd3e-98e5dd3277ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfTreasuryStock_01a1786c-730d-71e3-a6f3-f6625d08d441" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfTreasuryStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17868-03e2-7fad-97de-60592f916d7a" xlink:to="loc_us-gaap_ProceedsFromSaleOfTreasuryStock_01a1786c-730d-71e3-a6f3-f6625d08d441" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/AccumulatedOtherComprehensiveLossDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#AccumulatedOtherComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/AccumulatedOtherComprehensiveLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019fb94e-de33-7e78-8d15-e2af73c889f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019fb94e-de33-7e78-8d15-e2af73c889f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fb94e-de33-7a1c-bfba-bab3a345a1f0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:to="loc_us-gaap_EquityComponentDomain_019fb94e-de33-7a1c-bfba-bab3a345a1f0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:to="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fb94e-de33-79d2-9716-a19460bea494" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fb94e-de33-79d2-9716-a19460bea494" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019fb94e-de33-74cf-85e4-44f0960cad78" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019fb94e-de33-74cf-85e4-44f0960cad78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fb94e-de33-7466-a99a-3703656f9427" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fb94e-de33-7466-a99a-3703656f9427" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-783e-ab22-5c0a89e342b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-783e-ab22-5c0a89e342b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax_01a17876-6690-7522-b8ca-d92335c5b0bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax_01a17876-6690-7522-b8ca-d92335c5b0bd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-77b2-a661-47cd9f818020" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-77b2-a661-47cd9f818020" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-773a-a9ad-23652ffd5e7d" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-773a-a9ad-23652ffd5e7d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_01a1787f-70bd-7bdb-bc05-7354c7146f85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_01a1787f-70bd-7bdb-bc05-7354c7146f85" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_01a17876-99ec-703e-9ee4-5f715e712d43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_01a17876-99ec-703e-9ee4-5f715e712d43" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_01a17876-6690-7d86-82b0-b3fc57b3ae2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_01a17876-6690-7d86-82b0-b3fc57b3ae2c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_01a17876-6690-7c9e-8405-031757f5a67f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_01a17876-6690-7c9e-8405-031757f5a67f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a1787a-d0f8-7e71-bd4b-1ec1cbbda011" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a1787a-d0f8-7e71-bd4b-1ec1cbbda011" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_01a1787a-d0f8-7944-873a-f3a612480ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_01a1787a-d0f8-7944-873a-f3a612480ea4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax_01a17876-6690-74af-90dd-9517fa45c89d" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax_01a17876-6690-74af-90dd-9517fa45c89d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_01a17876-6690-77c9-bd5b-8d93ff5bad49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_01a17876-6690-77c9-bd5b-8d93ff5bad49" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a17876-6690-7265-82e8-9261451ba34a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a17876-6690-7265-82e8-9261451ba34a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-77b0-b45b-26fac8025399" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/AccumulatedOtherComprehensiveLossDetails_1" xlink:type="simple" xlink:href="xyl-20260930.xsd#AccumulatedOtherComprehensiveLossDetails_1"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/AccumulatedOtherComprehensiveLossDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019fb94e-de33-7930-899b-66c1ae51ca02" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fb94e-de33-7a1c-bfba-bab3a345a1f0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:to="loc_us-gaap_EquityComponentDomain_019fb94e-de33-7a1c-bfba-bab3a345a1f0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fb94e-de33-7a1c-bfba-bab3a345a1f0" xlink:to="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fb94e-de33-72f1-aad5-7740f3acb9db" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fb94e-de33-79d2-9716-a19460bea494" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fb94e-de33-79d2-9716-a19460bea494" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019fb94e-de33-74cf-85e4-44f0960cad78" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019fb94e-de33-74cf-85e4-44f0960cad78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fb94e-de33-7466-a99a-3703656f9427" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fb94e-de33-7a12-867e-e86de79ebfa3" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fb94e-de33-7466-a99a-3703656f9427" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019fb94e-de33-78a9-8628-63cfa8f40622" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-783e-ab22-5c0a89e342b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-783e-ab22-5c0a89e342b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax_01a17876-6690-7522-b8ca-d92335c5b0bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossBeforeReclassificationAndTax_01a17876-6690-7522-b8ca-d92335c5b0bd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-77b2-a661-47cd9f818020" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-77b2-a661-47cd9f818020" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-773a-a9ad-23652ffd5e7d" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationGainLossDivestitureBeforeReclassificationAndTax_01a17876-6690-773a-a9ad-23652ffd5e7d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_01a1787f-70bd-7bdb-bc05-7354c7146f85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_01a1787f-70bd-7bdb-bc05-7354c7146f85" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_01a17876-99ec-703e-9ee4-5f715e712d43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_01a17876-99ec-703e-9ee4-5f715e712d43" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_01a17876-6690-7d86-82b0-b3fc57b3ae2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_01a17876-6690-7d86-82b0-b3fc57b3ae2c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_01a17876-6690-7c9e-8405-031757f5a67f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_01a17876-6690-7c9e-8405-031757f5a67f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a1787a-d0f8-7e71-bd4b-1ec1cbbda011" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossDefinedBenefitPlanForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a1787a-d0f8-7e71-bd4b-1ec1cbbda011" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_01a1787a-d0f8-7944-873a-f3a612480ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax_01a1787a-d0f8-7944-873a-f3a612480ea4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax_01a17876-6690-74af-90dd-9517fa45c89d" xlink:href="xyl-20260930.xsd#xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_xyl_OtherComprehensiveIncomeLossForeignExchangeForPensionAndNonPensionPostretirementBenefitPlansBeforeTax_01a17876-6690-74af-90dd-9517fa45c89d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_01a17876-6690-77c9-bd5b-8d93ff5bad49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax_01a17876-6690-77c9-bd5b-8d93ff5bad49" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a17876-6690-7265-82e8-9261451ba34a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019fb94e-de33-7ca6-87c1-5e1e2f80252b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax_01a17876-6690-7265-82e8-9261451ba34a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019fb94e-de33-77b0-b45b-26fac8025399" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#CommitmentsandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_01a1789b-4c0d-72cb-845b-99776802676d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_01a1789b-4c0d-7663-9807-ee9ca1c461a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_01a1789b-4c0d-72cb-845b-99776802676d" xlink:to="loc_us-gaap_LossContingenciesTable_01a1789b-4c0d-7663-9807-ee9ca1c461a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_01a1789b-4c0d-711c-a81f-af7340d1b012" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_01a1789b-4c0d-7663-9807-ee9ca1c461a6" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_01a1789b-4c0d-711c-a81f-af7340d1b012" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_01a1789b-4c0d-711c-a81f-af7340d1b012_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_01a1789b-4c0d-711c-a81f-af7340d1b012" xlink:to="loc_us-gaap_LossContingencyNatureDomain_01a1789b-4c0d-711c-a81f-af7340d1b012_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_01a1789b-4c0d-706d-9716-bee78174dd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_01a1789b-4c0d-711c-a81f-af7340d1b012" xlink:to="loc_us-gaap_LossContingencyNatureDomain_01a1789b-4c0d-706d-9716-bee78174dd0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_EnvironmentalContingenciesMember_01a1789b-a39f-7e25-bef8-be4831c5d117" xlink:href="xyl-20260930.xsd#xyl_EnvironmentalContingenciesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_01a1789b-4c0d-706d-9716-bee78174dd0e" xlink:to="loc_xyl_EnvironmentalContingenciesMember_01a1789b-a39f-7e25-bef8-be4831c5d117" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019fb94e-de33-7440-b258-7e6a09dbc91a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_01a1789b-4c0d-72cb-845b-99776802676d" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019fb94e-de33-7440-b258-7e6a09dbc91a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019fb94e-de33-7cfe-98aa-4e828d0e804c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_01a1789b-4c0d-72cb-845b-99776802676d" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019fb94e-de33-7cfe-98aa-4e828d0e804c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyExpense_019fb94e-de33-7227-a24a-194badf8b545" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductWarrantyExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_01a1789b-4c0d-72cb-845b-99776802676d" xlink:to="loc_us-gaap_ProductWarrantyExpense_019fb94e-de33-7227-a24a-194badf8b545" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/SegmentandGeographicDataCODMDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#SegmentandGeographicDataCODMDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/SegmentandGeographicDataCODMDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fb94e-de33-714b-bba6-16f83005317f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fb94e-de33-714b-bba6-16f83005317f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-de33-724b-8c4f-eb6881a83033" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fb94e-de33-714b-bba6-16f83005317f" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-de33-724b-8c4f-eb6881a83033" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-de33-724b-8c4f-eb6881a83033_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-de33-724b-8c4f-eb6881a83033" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-de33-724b-8c4f-eb6881a83033_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fb94e-de33-724b-8c4f-eb6881a83033" xlink:to="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterInfrastructureSegmentMember_01a1561d-7ee7-7ffe-9b42-9f0f7f3d0c45" xlink:href="xyl-20260930.xsd#xyl_WaterInfrastructureSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_WaterInfrastructureSegmentMember_01a1561d-7ee7-7ffe-9b42-9f0f7f3d0c45" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterMember_019fb94e-de33-73aa-838c-6e9718a0a501" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_AppliedWaterMember_019fb94e-de33-73aa-838c-6e9718a0a501" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-de33-7424-b7f1-035245f3f507" xlink:href="xyl-20260930.xsd#xyl_MeasurementandControlSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_MeasurementandControlSolutionsMember_019fb94e-de33-7424-b7f1-035245f3f507" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-de33-7097-b20a-ba16f96973e8" xlink:href="xyl-20260930.xsd#xyl_WaterSolutionsServicesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_WaterSolutionsServicesSegmentMember_019fb94e-de33-7097-b20a-ba16f96973e8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_AppliedWaterSegmentMember_01a1561e-d6d6-7d56-aea1-9437ded62567" xlink:href="xyl-20260930.xsd#xyl_AppliedWaterSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_AppliedWaterSegmentMember_01a1561e-d6d6-7d56-aea1-9437ded62567" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_MeasurementAndControlSolutionsSegmentMember_01a1561e-d6d6-7941-8042-8749960ee17b" xlink:href="xyl-20260930.xsd#xyl_MeasurementAndControlSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_MeasurementAndControlSolutionsSegmentMember_01a1561e-d6d6-7941-8042-8749960ee17b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateAndOtherMember_01a1561e-d6d6-7979-99db-3a9f8e31a596" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_us-gaap_CorporateAndOtherMember_01a1561e-d6d6-7979-99db-3a9f8e31a596" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RegionalSellingLocationsMember_01a1561e-d6d6-7fad-9d80-09c7ab9992db" xlink:href="xyl-20260930.xsd#xyl_RegionalSellingLocationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fb94e-de33-7dd5-be95-e77d35c608e2" xlink:to="loc_xyl_RegionalSellingLocationsMember_01a1561e-d6d6-7fad-9d80-09c7ab9992db" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019fb94e-de33-7fd3-87eb-6f64cee230bd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fb94e-de33-714b-bba6-16f83005317f" xlink:to="loc_srt_ConsolidationItemsAxis_019fb94e-de33-7fd3-87eb-6f64cee230bd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019fb94e-de33-7fd3-87eb-6f64cee230bd_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019fb94e-de33-7fd3-87eb-6f64cee230bd" xlink:to="loc_srt_ConsolidationItemsDomain_019fb94e-de33-7fd3-87eb-6f64cee230bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019fb94e-de33-7448-8ff1-9aa4fa906ecd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019fb94e-de33-7fd3-87eb-6f64cee230bd" xlink:to="loc_srt_ConsolidationItemsDomain_019fb94e-de33-7448-8ff1-9aa4fa906ecd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019fb94e-de33-7559-8101-ea0783b65643" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019fb94e-de33-7448-8ff1-9aa4fa906ecd" xlink:to="loc_us-gaap_OperatingSegmentsMember_019fb94e-de33-7559-8101-ea0783b65643" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_01a17880-6c89-7309-8233-ff36d2d33849" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_NumberOfReportableSegments_01a17880-6c89-7309-8233-ff36d2d33849" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fb94e-de33-709b-9e97-ec6456639957" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019fb94e-de33-709b-9e97-ec6456639957" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019fb94e-de33-72b0-8670-ebdadff3c38e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_CostOfRevenue_019fb94e-de33-72b0-8670-ebdadff3c38e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019fb94e-de33-7601-8191-d65650245e7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_OperatingExpenses_019fb94e-de33-7601-8191-d65650245e7a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019fb94e-de33-7de5-b6e4-5c55a640aae3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019fb94e-de33-7de5-b6e4-5c55a640aae3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fb94e-de33-7ca4-8fd6-33e22ed60b23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_OperatingIncomeLoss_019fb94e-de33-7ca4-8fd6-33e22ed60b23" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_CorporateAndOtherLoss_019fb94e-de33-7cd7-9894-c529e247b7c5" xlink:href="xyl-20260930.xsd#xyl_CorporateAndOtherLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_xyl_CorporateAndOtherLoss_019fb94e-de33-7cd7-9894-c529e247b7c5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fb94e-de33-7aaf-aa38-4c2108a7c317" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fb94e-de33-7aaf-aa38-4c2108a7c317" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019fb94e-de33-7be7-a34e-31a2bdb0a28b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019fb94e-de33-7be7-a34e-31a2bdb0a28b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_019fb94e-de33-7530-ab91-aff534452b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_019fb94e-de33-7530-ab91-aff534452b1a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a14633-67d2-7ae9-b10b-101eef6e5b73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a14633-67d2-7ae9-b10b-101eef6e5b73" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_01a1561e-d6d6-70d4-a4aa-91321745389e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_01a1561e-d6d6-70d4-a4aa-91321745389e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_01a1561f-82dd-79c3-b9eb-1f8689bca1d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fb94e-de33-7f2f-b009-498d828dd323" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_01a1561f-82dd-79c3-b9eb-1f8689bca1d4" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.xyleminc.com/role/RedeemableNoncontrollingInterestsNarrativeDetails" xlink:type="simple" xlink:href="xyl-20260930.xsd#RedeemableNoncontrollingInterestsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.xyleminc.com/role/RedeemableNoncontrollingInterestsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_01a17881-79f7-7b91-97e6-358949d51c93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_01a17881-79f7-7457-bfea-d1294cd856db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17881-79f7-7b91-97e6-358949d51c93" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_01a17881-79f7-7457-bfea-d1294cd856db" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a17881-79f7-7359-abd7-28d1f8b915a9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_01a17881-79f7-7457-bfea-d1294cd856db" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a17881-79f7-7359-abd7-28d1f8b915a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a17881-79f7-7359-abd7-28d1f8b915a9_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a17881-79f7-7359-abd7-28d1f8b915a9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a17881-79f7-7359-abd7-28d1f8b915a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a17881-79f7-7ed1-ac8b-d758a074dcbb" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a17881-79f7-7359-abd7-28d1f8b915a9" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a17881-79f7-7ed1-ac8b-d758a074dcbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_GlobalOmniumIdricaS.L.Member_01a17881-79f7-744e-8348-a628609eb0d7" xlink:href="xyl-20260930.xsd#xyl_GlobalOmniumIdricaS.L.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_01a17881-79f7-7ed1-ac8b-d758a074dcbb" xlink:to="loc_xyl_GlobalOmniumIdricaS.L.Member_01a17881-79f7-744e-8348-a628609eb0d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RedeemableNoncontrollingInterestFixedStrikePrice_01a17881-79f7-7313-af24-2dcaedc82fdc" xlink:href="xyl-20260930.xsd#xyl_RedeemableNoncontrollingInterestFixedStrikePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17881-79f7-7b91-97e6-358949d51c93" xlink:to="loc_xyl_RedeemableNoncontrollingInterestFixedStrikePrice_01a17881-79f7-7313-af24-2dcaedc82fdc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_xyl_RedeemableNoncontrollingInterestFixedStrikePricePeriod_01a17881-9c16-76fd-ac7c-cf758b162922" xlink:href="xyl-20260930.xsd#xyl_RedeemableNoncontrollingInterestFixedStrikePricePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_01a17881-79f7-7b91-97e6-358949d51c93" xlink:to="loc_xyl_RedeemableNoncontrollingInterestFixedStrikePricePeriod_01a17881-9c16-76fd-ac7c-cf758b162922" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1"/>
  <link:definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_AccountsPayableCurrent" xlink:type="arc" order="31"/>
  </link:definitionLink>
</link:linkbase>
