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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f4274-b278-714d-998c-38f370ca6aaf,g:c216d028-55fa-44ac-94d1-bb5c7ed24ecc-->
<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.cpr.ca/role/Cover" xlink:type="simple" xlink:href="cp-20260630.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_019f4274-b33c-7580-a8ec-a436bd5c3182" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntitiesTable_019f4274-b33c-7580-a8ec-a436bd5c3182" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019f4274-b33c-77cd-bce4-b5b269d8b051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_019f4274-b33c-7580-a8ec-a436bd5c3182" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019f4274-b33c-77cd-bce4-b5b269d8b051" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-77cd-bce4-b5b269d8b051_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019f4274-b33c-77cd-bce4-b5b269d8b051" xlink:to="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-77cd-bce4-b5b269d8b051_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-796e-8c50-f52d73f20908" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019f4274-b33c-77cd-bce4-b5b269d8b051" xlink:to="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-796e-8c50-f52d73f20908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019f4274-b33c-712e-8e6f-72a3e22be6f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-796e-8c50-f52d73f20908" xlink:to="loc_us-gaap_CommonClassAMember_019f4274-b33c-712e-8e6f-72a3e22be6f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_Perpetual4ConsolidatedDebentureStockMember_019f4274-b33c-7304-9488-46e4c1ee830a" xlink:href="cp-20260630.xsd#cp_Perpetual4ConsolidatedDebentureStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019f4274-b33c-796e-8c50-f52d73f20908" xlink:to="loc_cp_Perpetual4ConsolidatedDebentureStockMember_019f4274-b33c-7304-9488-46e4c1ee830a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsExchangeAxis_019f4274-b33c-7235-85c4-5870855669a2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityListingsExchangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_019f4274-b33c-7580-a8ec-a436bd5c3182" xlink:to="loc_dei_EntityListingsExchangeAxis_019f4274-b33c-7235-85c4-5870855669a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_ExchangeDomain_019f4274-b33c-7235-85c4-5870855669a2_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_ExchangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_EntityListingsExchangeAxis_019f4274-b33c-7235-85c4-5870855669a2" xlink:to="loc_dei_ExchangeDomain_019f4274-b33c-7235-85c4-5870855669a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_ExchangeDomain_019f4274-b33c-718d-861f-4834eea656f5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_ExchangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_EntityListingsExchangeAxis_019f4274-b33c-7235-85c4-5870855669a2" xlink:to="loc_dei_ExchangeDomain_019f4274-b33c-718d-861f-4834eea656f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_exch_XNYS_019f4274-b33c-7aec-9bfe-036c504e2b5a" xlink:href="https://xbrl.sec.gov/exch/2026/exch-2026.xsd#exch_XNYS"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_ExchangeDomain_019f4274-b33c-718d-861f-4834eea656f5" xlink:to="loc_exch_XNYS_019f4274-b33c-7aec-9bfe-036c504e2b5a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_exch_XTSE_019f4274-b33c-7ebe-8ec0-d070879acee1" xlink:href="https://xbrl.sec.gov/exch/2026/exch-2026.xsd#exch_XTSE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_ExchangeDomain_019f4274-b33c-718d-861f-4834eea656f5" xlink:to="loc_exch_XTSE_019f4274-b33c-7ebe-8ec0-d070879acee1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_exch_XLON_019f4274-b33c-7d73-a957-e91562c7e49e" xlink:href="https://xbrl.sec.gov/exch/2026/exch-2026.xsd#exch_XLON"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_ExchangeDomain_019f4274-b33c-718d-861f-4834eea656f5" xlink:to="loc_exch_XLON_019f4274-b33c-7d73-a957-e91562c7e49e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019f4274-b33c-792b-b41d-2afb0b631e57" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentType_019f4274-b33c-792b-b41d-2afb0b631e57" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019f4274-b33c-7e74-a6c3-8e734e01ccb9" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentQuarterlyReport_019f4274-b33c-7e74-a6c3-8e734e01ccb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019f4274-b33c-7018-8e08-8708bcb4c585" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentPeriodEndDate_019f4274-b33c-7018-8e08-8708bcb4c585" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019f4274-b33c-7365-9407-e9022702b8bd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentTransitionReport_019f4274-b33c-7365-9407-e9022702b8bd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019f4274-b33c-7906-b884-f92e96ffca24" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityFileNumber_019f4274-b33c-7906-b884-f92e96ffca24" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019f4274-b33c-7216-b45a-75a5ef85a181" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityRegistrantName_019f4274-b33c-7216-b45a-75a5ef85a181" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019f4274-b33c-79cc-9dfc-18572acc0a90" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019f4274-b33c-79cc-9dfc-18572acc0a90" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019f4274-b33c-77c8-a4fa-1593136597aa" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityTaxIdentificationNumber_019f4274-b33c-77c8-a4fa-1593136597aa" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019f4274-b33c-7436-abc0-8e385489520c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityAddressAddressLine1_019f4274-b33c-7436-abc0-8e385489520c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019f4274-b33c-70c9-b376-771dee4b1534" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityAddressCityOrTown_019f4274-b33c-70c9-b376-771dee4b1534" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019f4274-b33c-7b95-926f-3f397f8bdb11" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityAddressStateOrProvince_019f4274-b33c-7b95-926f-3f397f8bdb11" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCountry_019f4274-b33c-7a1d-892c-108911999a7c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCountry"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityAddressCountry_019f4274-b33c-7a1d-892c-108911999a7c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019f4274-b33c-7a7f-b7a3-9adcfc28ad32" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityAddressPostalZipCode_019f4274-b33c-7a7f-b7a3-9adcfc28ad32" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019f4274-b33c-79de-b9e0-65de01144252" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_CityAreaCode_019f4274-b33c-79de-b9e0-65de01144252" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019f4274-b33c-7d7b-b361-762d40531c4b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_LocalPhoneNumber_019f4274-b33c-7d7b-b361-762d40531c4b" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019f4274-b33c-7dbe-922f-38f7e0289def" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_Security12bTitle_019f4274-b33c-7dbe-922f-38f7e0289def" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019f4274-b33c-7e35-8f90-a3be7bc1e685" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_TradingSymbol_019f4274-b33c-7e35-8f90-a3be7bc1e685" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019f4274-b33c-7dc8-85d5-95b9ce15316d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_SecurityExchangeName_019f4274-b33c-7dc8-85d5-95b9ce15316d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019f4274-b33c-74ab-ab0d-e8f1467ea7d0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityCurrentReportingStatus_019f4274-b33c-74ab-ab0d-e8f1467ea7d0" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019f4274-b33c-7966-a39b-143ff316d55f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityInteractiveDataCurrent_019f4274-b33c-7966-a39b-143ff316d55f" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019f4274-b33c-7a16-8a46-7ba78b32d3e0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityFilerCategory_019f4274-b33c-7a16-8a46-7ba78b32d3e0" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019f4274-b33c-7c50-811c-195e03b623aa" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntitySmallBusiness_019f4274-b33c-7c50-811c-195e03b623aa" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019f4274-b33c-741c-ba1d-bdd1ffca40a0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityEmergingGrowthCompany_019f4274-b33c-741c-ba1d-bdd1ffca40a0" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019f4274-b33c-7e32-ae22-29da4dc97f3b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityShellCompany_019f4274-b33c-7e32-ae22-29da4dc97f3b" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019f4274-b33c-7ce1-8dda-6a3f3f03276b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019f4274-b33c-7ce1-8dda-6a3f3f03276b" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019f4274-b33c-748b-83ae-d94f641eb6ca" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_AmendmentFlag_019f4274-b33c-748b-83ae-d94f641eb6ca" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019f4274-b33c-79d8-bcb2-c54f609d3c04" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentFiscalYearFocus_019f4274-b33c-79d8-bcb2-c54f609d3c04" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019f4274-b33c-7d21-8fc1-98f1b790dc60" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019f4274-b33c-7d21-8fc1-98f1b790dc60" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019f4274-b33c-776e-9226-c29319741dda" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_EntityCentralIndexKey_019f4274-b33c-776e-9226-c29319741dda" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019f4274-b33c-7425-ac5b-ff4d3dc35066" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019f4274-b33c-7f46-bfb6-3cb6726c0e76" xlink:to="loc_dei_CurrentFiscalYearEndDate_019f4274-b33c-7425-ac5b-ff4d3dc35066" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/INTERIMCONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="cp-20260630.xsd#INTERIMCONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/INTERIMCONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" 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_019f4274-b33c-715f-806b-fff4a8d131ce" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_StatementTable_019f4274-b33c-715f-806b-fff4a8d131ce" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f4274-b33c-719b-b378-0de80f86ab87" 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_019f4274-b33c-715f-806b-fff4a8d131ce" xlink:to="loc_srt_ProductOrServiceAxis_019f4274-b33c-719b-b378-0de80f86ab87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f4274-b33c-719b-b378-0de80f86ab87_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_019f4274-b33c-719b-b378-0de80f86ab87" xlink:to="loc_srt_ProductsAndServicesDomain_019f4274-b33c-719b-b378-0de80f86ab87_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f4274-b33c-712e-9fec-e9071bb268a5" 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_019f4274-b33c-719b-b378-0de80f86ab87" xlink:to="loc_srt_ProductsAndServicesDomain_019f4274-b33c-712e-9fec-e9071bb268a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CargoAndFreightMember_019f4274-b33c-7ecc-8fcd-c8ab7b7c1b40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CargoAndFreightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f4274-b33c-712e-9fec-e9071bb268a5" xlink:to="loc_us-gaap_CargoAndFreightMember_019f4274-b33c-7ecc-8fcd-c8ab7b7c1b40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_NonFreightMember_019f4274-b33c-782f-9719-cad5d5e0f4b4" xlink:href="cp-20260630.xsd#cp_NonFreightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f4274-b33c-712e-9fec-e9071bb268a5" xlink:to="loc_cp_NonFreightMember_019f4274-b33c-782f-9719-cad5d5e0f4b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019f4274-b33c-75bf-a4a2-681128c8c9f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_RevenuesAbstract_019f4274-b33c-75bf-a4a2-681128c8c9f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f4274-b33c-7798-8f47-1f545575d024" 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_RevenuesAbstract_019f4274-b33c-75bf-a4a2-681128c8c9f6" xlink:to="loc_us-gaap_Revenues_019f4274-b33c-7798-8f47-1f545575d024" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019f4274-b33c-7b7b-b2a6-25b02f81eebc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019f4274-b33c-7b7b-b2a6-25b02f81eebc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FuelCosts_019f4274-b33c-7a62-a44b-1445e7444be5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FuelCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_us-gaap_FuelCosts_019f4274-b33c-7a62-a44b-1445e7444be5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostDirectMaterial_019f4274-b33c-73f8-991f-cfd3e1368f60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostDirectMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_us-gaap_CostDirectMaterial_019f4274-b33c-73f8-991f-cfd3e1368f60" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_EquipmentRents_019f4274-b33c-72ef-8bfe-d961052dea52" xlink:href="cp-20260630.xsd#cp_EquipmentRents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_cp_EquipmentRents_019f4274-b33c-72ef-8bfe-d961052dea52" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019f4274-b33c-7a18-b723-566fb42e6786" 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_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019f4274-b33c-7a18-b723-566fb42e6786" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PurchasedServicesandOther_019f4274-b33c-7bd8-a280-2fbc8fe004e3" xlink:href="cp-20260630.xsd#cp_PurchasedServicesandOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_cp_PurchasedServicesandOther_019f4274-b33c-7bd8-a280-2fbc8fe004e3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019f4274-b33c-7af3-a324-e5caf79d70a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f4274-b33c-70f1-80c5-33d83a2293f5" xlink:to="loc_us-gaap_CostsAndExpenses_019f4274-b33c-7af3-a324-e5caf79d70a0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f4274-b33c-7415-8ea8-5663a314376d" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f4274-b33c-7415-8ea8-5663a314376d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019f4274-b33c-7880-8ed3-66a12c9c7765" 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_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019f4274-b33c-7880-8ed3-66a12c9c7765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_019f4274-b33c-771b-8e54-448d1f826600" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:to="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_019f4274-b33c-771b-8e54-448d1f826600" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019f4274-b33c-7073-831d-732160cd244e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_019f4274-b33c-7073-831d-732160cd244e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f7044-7cb4-73e6-b407-a34a4f31c6dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f4274-b33c-7f50-9df9-efc41aa8c3fa" xlink:to="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f7044-7cb4-73e6-b407-a34a4f31c6dd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f4274-b33c-7852-b4c8-2e623504615e" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f4274-b33c-7852-b4c8-2e623504615e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_019f4274-b33c-7575-a2fd-826bd1b17cd8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_019f4274-b33c-7575-a2fd-826bd1b17cd8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019f4274-b33c-7413-8c47-3c29db52fede" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_019f4274-b33c-7575-a2fd-826bd1b17cd8" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019f4274-b33c-7413-8c47-3c29db52fede" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019f4274-b33c-7a24-a0b4-0cc3ca2993ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAbstract_019f4274-b33c-7575-a2fd-826bd1b17cd8" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019f4274-b33c-7a24-a0b4-0cc3ca2993ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019f4274-b33c-721f-9f2f-3878913cb421" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019f4274-b33c-721f-9f2f-3878913cb421" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019f4274-b33c-7072-89ef-f5e07495f218" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_ProfitLoss_019f4274-b33c-7072-89ef-f5e07495f218" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f4274-b33c-7b55-84f7-33ca9686c80e" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f4274-b33c-7b55-84f7-33ca9686c80e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f4274-b33c-7942-9ca5-7f64d3238b91" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_NetIncomeLoss_019f4274-b33c-7942-9ca5-7f64d3238b91" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019f4274-b33c-7440-97eb-a3d70166b679" 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_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019f4274-b33c-7440-97eb-a3d70166b679" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019f4274-b33c-7d33-9d28-d54c0e982113" 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_019f4274-b33c-7440-97eb-a3d70166b679" xlink:to="loc_us-gaap_EarningsPerShareBasic_019f4274-b33c-7d33-9d28-d54c0e982113" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f4274-b33c-792a-85b0-c69399d8cbe2" 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_019f4274-b33c-7440-97eb-a3d70166b679" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f4274-b33c-792a-85b0-c69399d8cbe2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f4274-b33c-7dd5-b6b1-9fa243d656bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f4274-b33c-7dd5-b6b1-9fa243d656bd" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f4274-b33c-7b6f-bd39-e4743d0954e5" 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_WeightedAverageNumberOfSharesOutstandingAbstract_019f4274-b33c-7dd5-b6b1-9fa243d656bd" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f4274-b33c-7b6f-bd39-e4743d0954e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f4274-b33c-754a-8b82-66dec47e1cd4" 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_WeightedAverageNumberOfSharesOutstandingAbstract_019f4274-b33c-7dd5-b6b1-9fa243d656bd" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f4274-b33c-754a-8b82-66dec47e1cd4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f4274-b33c-713c-919f-724a0a842fc3" 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_us-gaap_StatementLineItems_019f4274-b33c-7835-9103-8ddb9f28c149" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f4274-b33c-713c-919f-724a0a842fc3" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/INTERIMCONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY" xlink:type="simple" xlink:href="cp-20260630.xsd#INTERIMCONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/INTERIMCONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f4274-b3fd-7383-b7a4-c173ba2f3f0f" 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_019f4274-b3fd-7336-9fe8-380d7588b257" 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_019f4274-b3fd-7383-b7a4-c173ba2f3f0f" xlink:to="loc_us-gaap_StatementTable_019f4274-b3fd-7336-9fe8-380d7588b257" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f4274-b3fd-7256-87ed-af27a7c587d0" 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_StatementTable_019f4274-b3fd-7336-9fe8-380d7588b257" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f4274-b3fd-7256-87ed-af27a7c587d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-7256-87ed-af27a7c587d0_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_019f4274-b3fd-7256-87ed-af27a7c587d0" xlink:to="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-7256-87ed-af27a7c587d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-736f-8022-fda69626080b" 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_019f4274-b3fd-7256-87ed-af27a7c587d0" xlink:to="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-736f-8022-fda69626080b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-736f-8022-fda69626080b" xlink:to="loc_us-gaap_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019f4274-b3fd-7c95-88b1-3bae87cf239c" 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_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:to="loc_us-gaap_CommonStockMember_019f4274-b3fd-7c95-88b1-3bae87cf239c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019f4274-b3fd-7c62-8441-987988376d7f" 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_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019f4274-b3fd-7c62-8441-987988376d7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f4274-b3fd-7d96-a64c-393404ed7cc4" 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_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f4274-b3fd-7d96-a64c-393404ed7cc4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019f4274-b3fd-75b7-9fb8-e1e6aa22c459" 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_ParentMember_019f4274-b3fd-702f-bdc4-630d0d99aa21" xlink:to="loc_us-gaap_RetainedEarningsMember_019f4274-b3fd-75b7-9fb8-e1e6aa22c459" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019f4274-b3fd-79ec-aa08-bdd4079da437" 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_019f4274-b3fd-736f-8022-fda69626080b" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019f4274-b3fd-79ec-aa08-bdd4079da437" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" 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_us-gaap_StatementLineItems_019f4274-b3fd-7383-b7a4-c173ba2f3f0f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f4274-b3fd-79e2-b23a-be3f2b1cf28c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019f4274-b3fd-79e2-b23a-be3f2b1cf28c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-7106-96ea-bf55510551b7" 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_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-7106-96ea-bf55510551b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019f4274-b3fd-7357-83f4-e6e4261cfbc7" 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_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_ProfitLoss_019f4274-b3fd-7357-83f4-e6e4261cfbc7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance_019f4274-b3fd-7c55-8f8d-9a647d8e96f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance_019f4274-b3fd-7c55-8f8d-9a647d8e96f4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f4274-b3fd-739a-958b-94c0580e5c1f" 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_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f4274-b3fd-739a-958b-94c0580e5c1f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019f4274-b3fd-7947-87ce-c7d013fc2398" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_DividendsCommonStock_019f4274-b3fd-7947-87ce-c7d013fc2398" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f4274-b3fd-748d-b7de-99063384cc6d" 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_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f4274-b3fd-748d-b7de-99063384cc6d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f4274-b3fd-7bb2-ac10-552b0b2423de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f4274-b3fd-7bb2-ac10-552b0b2423de" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f4274-b3fd-77a6-8538-1e8b15ada5c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f4274-b3fd-77a6-8538-1e8b15ada5c5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019f4274-b3fd-73b0-b241-7b000c50d097" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019f4274-b3fd-73b0-b241-7b000c50d097" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f4274-b3fd-7926-be76-1e7f75d42fa8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f4274-b3fd-7448-aeb4-c04afc564ccc" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f4274-b3fd-7926-be76-1e7f75d42fa8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f4274-b3fd-7f6f-98c7-6ff7a95f18b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-7f7a-9331-290e021116b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/RevenuesDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#RevenuesDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/RevenuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019f4274-b3fd-7190-91c4-7f75af8e4d47" 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_019f4274-b3fd-7123-8d2a-1f1a9a981c61" 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_019f4274-b3fd-7190-91c4-7f75af8e4d47" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019f4274-b3fd-7123-8d2a-1f1a9a981c61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f4274-b3fd-74d0-ae39-6b14b39b76d4" 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_019f4274-b3fd-7123-8d2a-1f1a9a981c61" xlink:to="loc_srt_ProductOrServiceAxis_019f4274-b3fd-74d0-ae39-6b14b39b76d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-74d0-ae39-6b14b39b76d4_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_019f4274-b3fd-74d0-ae39-6b14b39b76d4" xlink:to="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-74d0-ae39-6b14b39b76d4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-7604-a66c-3b8e9f043929" 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_019f4274-b3fd-74d0-ae39-6b14b39b76d4" xlink:to="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-7604-a66c-3b8e9f043929" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CargoAndFreightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-7604-a66c-3b8e9f043929" xlink:to="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_GrainRevenueMember_019f4274-b3fd-775d-ad36-ebcb09dc9ddc" xlink:href="cp-20260630.xsd#cp_GrainRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_GrainRevenueMember_019f4274-b3fd-775d-ad36-ebcb09dc9ddc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_CoalRevenueMember_019f4274-b3fd-781f-aaa2-7254e9c164a8" xlink:href="cp-20260630.xsd#cp_CoalRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_CoalRevenueMember_019f4274-b3fd-781f-aaa2-7254e9c164a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PotashRevenueMember_019f4274-b3fd-78d6-a9f6-074d28b267dc" xlink:href="cp-20260630.xsd#cp_PotashRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_PotashRevenueMember_019f4274-b3fd-78d6-a9f6-074d28b267dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_FertilizerandSulphurRevenueMember_019f4274-b3fd-7d3e-8326-3174c0653cc5" xlink:href="cp-20260630.xsd#cp_FertilizerandSulphurRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_FertilizerandSulphurRevenueMember_019f4274-b3fd-7d3e-8326-3174c0653cc5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ForestProductsRevenueMember_019f4274-b3fd-7a7e-a0d9-b70d9855c3ef" xlink:href="cp-20260630.xsd#cp_ForestProductsRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_ForestProductsRevenueMember_019f4274-b3fd-7a7e-a0d9-b70d9855c3ef" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_EnergyChemicalsandPlasticRevenueMember_019f4274-b3fd-79e6-a383-6bb1fc488b5b" xlink:href="cp-20260630.xsd#cp_EnergyChemicalsandPlasticRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_EnergyChemicalsandPlasticRevenueMember_019f4274-b3fd-79e6-a383-6bb1fc488b5b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_MetalsMineralsandConsumerProductsRevenueMember_019f4274-b3fd-7a66-91d4-df0114ddac76" xlink:href="cp-20260630.xsd#cp_MetalsMineralsandConsumerProductsRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_MetalsMineralsandConsumerProductsRevenueMember_019f4274-b3fd-7a66-91d4-df0114ddac76" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_AutomotiveMember_019f4274-b3fd-749a-ba6a-aeee6d88f2af" xlink:href="cp-20260630.xsd#cp_AutomotiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_AutomotiveMember_019f4274-b3fd-749a-ba6a-aeee6d88f2af" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_IntermodalMember_019f4274-b3fd-7236-a69c-da91a144b3ba" xlink:href="cp-20260630.xsd#cp_IntermodalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CargoAndFreightMember_019f4274-b3fd-7a78-a262-6fb6288946e7" xlink:to="loc_cp_IntermodalMember_019f4274-b3fd-7236-a69c-da91a144b3ba" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_NonfreightexcludingleasingrevenuesMember_019f4274-b3fd-799c-a95f-9b0c714df419" xlink:href="cp-20260630.xsd#cp_NonfreightexcludingleasingrevenuesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f4274-b3fd-7604-a66c-3b8e9f043929" xlink:to="loc_cp_NonfreightexcludingleasingrevenuesMember_019f4274-b3fd-799c-a95f-9b0c714df419" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f4274-b3fd-77d9-a960-3d9a76b69ac5" 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_DisaggregationOfRevenueLineItems_019f4274-b3fd-7190-91c4-7f75af8e4d47" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f4274-b3fd-77d9-a960-3d9a76b69ac5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseIncome_019f4274-b3fd-77d2-bd93-8593c49c9f35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019f4274-b3fd-7190-91c4-7f75af8e4d47" xlink:to="loc_us-gaap_LeaseIncome_019f4274-b3fd-77d2-bd93-8593c49c9f35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f4274-b3fd-79e2-8502-3b23411eaef6" 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_019f4274-b3fd-7190-91c4-7f75af8e4d47" xlink:to="loc_us-gaap_Revenues_019f4274-b3fd-79e2-8502-3b23411eaef6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/GainonsaleofequityinvestmentDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#GainonsaleofequityinvestmentDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/GainonsaleofequityinvestmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019f7201-2dd7-7e63-8aea-2d8706918221" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_019f7201-2dd7-7e63-8aea-2d8706918221" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019f7204-aaf6-7db2-8fa1-df6188afc985" 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_ScheduleOfEquityMethodInvestmentsTable_019f7201-2dd7-7e63-8aea-2d8706918221" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019f7204-aaf6-7db2-8fa1-df6188afc985" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019f7204-aaf6-7db2-8fa1-df6188afc985_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_019f7204-aaf6-7db2-8fa1-df6188afc985" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019f7204-aaf6-7db2-8fa1-df6188afc985_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019f7204-aaf6-765b-ac5c-bcb1c74b7d5e" 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_019f7204-aaf6-7db2-8fa1-df6188afc985" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019f7204-aaf6-765b-ac5c-bcb1c74b7d5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PanamaCanalRailwayCompanyMember_019f7204-cf53-75ca-9a27-340bfd1a76f4" xlink:href="cp-20260630.xsd#cp_PanamaCanalRailwayCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019f7204-aaf6-765b-ac5c-bcb1c74b7d5e" xlink:to="loc_cp_PanamaCanalRailwayCompanyMember_019f7204-cf53-75ca-9a27-340bfd1a76f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_EquityMethodInvestmentOwnershipPercentageSold_019f7201-2dd7-70d5-adfb-92b41e59a086" xlink:href="cp-20260630.xsd#cp_EquityMethodInvestmentOwnershipPercentageSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_cp_EquityMethodInvestmentOwnershipPercentageSold_019f7201-2dd7-70d5-adfb-92b41e59a086" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_EquityMethodInvestmentsGrossSaleAmount_019f7206-b7a3-723a-bf80-aaa43b7ec76c" xlink:href="cp-20260630.xsd#cp_EquityMethodInvestmentsGrossSaleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_cp_EquityMethodInvestmentsGrossSaleAmount_019f7206-b7a3-723a-bf80-aaa43b7ec76c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments_019f7235-c124-7438-9595-69e5093962bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_us-gaap_ProceedsFromSaleOfEquityMethodInvestments_019f7235-c124-7438-9595-69e5093962bf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f7fc5-baf4-77d9-9737-ae5f931219c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f7fc5-baf4-77d9-9737-ae5f931219c7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_EquityMethodInvestmentRealizedGainLossOnDisposalAfterTax_019f7fc6-9abd-703d-b918-5690ad5a6be1" xlink:href="cp-20260630.xsd#cp_EquityMethodInvestmentRealizedGainLossOnDisposalAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_019f7201-2dd7-7241-9227-535b86f4186c" xlink:to="loc_cp_EquityMethodInvestmentRealizedGainLossOnDisposalAfterTax_019f7fc6-9abd-703d-b918-5690ad5a6be1" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/IncometaxesDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#IncometaxesDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/IncometaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f4274-b3fd-763b-8924-0b647905ad60" 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_019f4274-b3fd-731c-acad-d3667984c1bb" 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_019f4274-b3fd-763b-8924-0b647905ad60" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f4274-b3fd-731c-acad-d3667984c1bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f4274-b3fd-7780-82e3-1537664cfc35" 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_019f4274-b3fd-731c-acad-d3667984c1bb" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f4274-b3fd-7780-82e3-1537664cfc35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4274-b3fd-7780-82e3-1537664cfc35_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_019f4274-b3fd-7780-82e3-1537664cfc35" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4274-b3fd-7780-82e3-1537664cfc35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4274-b3fd-745b-b6a2-36d078f8df99" 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_019f4274-b3fd-7780-82e3-1537664cfc35" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4274-b3fd-745b-b6a2-36d078f8df99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_KansasCitySouthernMember_019f4274-b3fd-7cc4-b00c-8d1e299e4f65" xlink:href="cp-20260630.xsd#cp_KansasCitySouthernMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f4274-b3fd-745b-b6a2-36d078f8df99" xlink:to="loc_cp_KansasCitySouthernMember_019f4274-b3fd-7cc4-b00c-8d1e299e4f65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019f9060-f8b0-76f7-b19a-71149d7e019c" 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_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f4274-b3fd-731c-acad-d3667984c1bb" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019f9060-f8b0-76f7-b19a-71149d7e019c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019f9060-f8b0-76f7-b19a-71149d7e019c_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_019f9060-f8b0-76f7-b19a-71149d7e019c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019f9060-f8b0-76f7-b19a-71149d7e019c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019f9060-f8b0-77e7-84ea-3a3241aa8e0e" 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_019f9060-f8b0-76f7-b19a-71149d7e019c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019f9060-f8b0-77e7-84ea-3a3241aa8e0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PanamaCanalRailwayCompanyMember_019f9061-084f-7eb7-9c25-dfb003db484a" xlink:href="cp-20260630.xsd#cp_PanamaCanalRailwayCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019f9060-f8b0-77e7-84ea-3a3241aa8e0e" xlink:to="loc_cp_PanamaCanalRailwayCompanyMember_019f9061-084f-7eb7-9c25-dfb003db484a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f905f-460f-77bf-8309-0396abd99ddb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4274-b3fd-763b-8924-0b647905ad60" xlink:to="loc_us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_019f905f-460f-77bf-8309-0396abd99ddb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_BusinessCombinationAmortizationOfFairValueAdjustments_019f4274-b3fd-76fb-a7ed-a42946a0d996" xlink:href="cp-20260630.xsd#cp_BusinessCombinationAmortizationOfFairValueAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4274-b3fd-763b-8924-0b647905ad60" xlink:to="loc_cp_BusinessCombinationAmortizationOfFairValueAdjustments_019f4274-b3fd-76fb-a7ed-a42946a0d996" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f4274-b3fd-7bd8-bb62-acc04b7d62d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f4274-b3fd-763b-8924-0b647905ad60" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f4274-b3fd-7bd8-bb62-acc04b7d62d4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/EarningspershareNarrativeDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#EarningspershareNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/EarningspershareNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019f4274-b3fd-7130-8201-116cd6366a07" 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_019f4274-b3fd-705e-9665-2139638100db" 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_019f4274-b3fd-7130-8201-116cd6366a07" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019f4274-b3fd-705e-9665-2139638100db" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f4274-b3fd-754a-9d84-047c1be79c79" 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_019f4274-b3fd-705e-9665-2139638100db" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f4274-b3fd-754a-9d84-047c1be79c79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f4274-b3fd-754a-9d84-047c1be79c79_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_019f4274-b3fd-754a-9d84-047c1be79c79" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f4274-b3fd-754a-9d84-047c1be79c79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f4274-b3fd-791d-8b58-992742dddc50" 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_019f4274-b3fd-754a-9d84-047c1be79c79" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f4274-b3fd-791d-8b58-992742dddc50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019f4274-b3fd-73bc-8c07-c0cc386f18a3" 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_019f4274-b3fd-791d-8b58-992742dddc50" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019f4274-b3fd-73bc-8c07-c0cc386f18a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f4274-b3fd-7e88-ba61-1f8cef35fa9b" 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_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019f4274-b3fd-7130-8201-116cd6366a07" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f4274-b3fd-7e88-ba61-1f8cef35fa9b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/ChangesinAccumulatedothercomprehensiveincomeAOCIbycomponentDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#ChangesinAccumulatedothercomprehensiveincomeAOCIbycomponentDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/ChangesinAccumulatedothercomprehensiveincomeAOCIbycomponentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f4274-b3fd-7130-ba71-1e15bfc33668" 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_019f4274-b3fd-7f9b-a561-e53c541adbc8" 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_019f4274-b3fd-7130-ba71-1e15bfc33668" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f4274-b3fd-7f9b-a561-e53c541adbc8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f4274-b3fd-715e-86cb-e2e6824d4f1c" 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_019f4274-b3fd-7f9b-a561-e53c541adbc8" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f4274-b3fd-715e-86cb-e2e6824d4f1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-715e-86cb-e2e6824d4f1c_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_019f4274-b3fd-715e-86cb-e2e6824d4f1c" xlink:to="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-715e-86cb-e2e6824d4f1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-7e59-8634-8966b664b3a8" 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_019f4274-b3fd-715e-86cb-e2e6824d4f1c" xlink:to="loc_us-gaap_EquityComponentDomain_019f4274-b3fd-7e59-8634-8966b664b3a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f4274-b3fd-7d1c-9d07-244ca268a7a1" 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_019f4274-b3fd-7e59-8634-8966b664b3a8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f4274-b3fd-7d1c-9d07-244ca268a7a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019f4274-b3fd-7f24-921d-71fb3b7987d3" 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_019f4274-b3fd-7d1c-9d07-244ca268a7a1" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019f4274-b3fd-7f24-921d-71fb3b7987d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f4274-b3fd-7b1e-be3b-e4b29ea0d874" 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_019f4274-b3fd-7d1c-9d07-244ca268a7a1" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f4274-b3fd-7b1e-be3b-e4b29ea0d874" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019f4274-b3fd-7f71-8ad7-672c8b4d1b48" 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_019f4274-b3fd-7d1c-9d07-244ca268a7a1" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019f4274-b3fd-7f71-8ad7-672c8b4d1b48" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociEquityMethodInvestmentParentMember_019f4274-b3fd-7973-8101-ef898395566d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AociEquityMethodInvestmentParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f4274-b3fd-7d1c-9d07-244ca268a7a1" xlink:to="loc_us-gaap_AociEquityMethodInvestmentParentMember_019f4274-b3fd-7973-8101-ef898395566d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019f4274-b3fd-7134-912f-e9f7947512d6" 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_019f4274-b3fd-7130-ba71-1e15bfc33668" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019f4274-b3fd-7134-912f-e9f7947512d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-740f-8364-c418a1d1cafb" 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_019f4274-b3fd-7134-912f-e9f7947512d6" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-740f-8364-c418a1d1cafb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019f4274-b3fd-7775-8e3b-92fc904a979c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019f4274-b3fd-7134-912f-e9f7947512d6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019f4274-b3fd-7775-8e3b-92fc904a979c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019f4274-b3fd-7c54-828d-0fbb3054a891" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019f4274-b3fd-7134-912f-e9f7947512d6" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019f4274-b3fd-7c54-828d-0fbb3054a891" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f4274-b3fd-7cb1-9611-e86c8ca470de" 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_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract_019f4274-b3fd-7134-912f-e9f7947512d6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f4274-b3fd-7cb1-9611-e86c8ca470de" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f4274-b3fd-76ab-ba8c-9a0fb1b3714a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/DebtDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#DebtDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f4274-b3fe-7b73-8435-17b092184562" 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_019f4274-b3fe-7e23-b5b9-1dab47e7ebc1" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_DebtInstrumentTable_019f4274-b3fe-7e23-b5b9-1dab47e7ebc1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f4274-b3fe-7076-821a-9c3944c7df72" 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_019f4274-b3fe-7e23-b5b9-1dab47e7ebc1" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f4274-b3fe-7076-821a-9c3944c7df72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-7076-821a-9c3944c7df72_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_019f4274-b3fe-7076-821a-9c3944c7df72" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-7076-821a-9c3944c7df72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" 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_019f4274-b3fe-7076-821a-9c3944c7df72" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A3.70010.5YearNotesMember_019f4274-b3fe-7cc7-bfcf-cc3b202865ca" xlink:href="cp-20260630.xsd#cp_A3.70010.5YearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A3.70010.5YearNotesMember_019f4274-b3fe-7cc7-bfcf-cc3b202865ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A3.12510YearNotesMember_019f7fd2-f6a9-72c4-adb8-dc68a349e86d" xlink:href="cp-20260630.xsd#cp_A3.12510YearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A3.12510YearNotesMember_019f7fd2-f6a9-72c4-adb8-dc68a349e86d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A4.003YearNoteMember_019f4274-b3fe-7568-bc75-22df8b1901ff" xlink:href="cp-20260630.xsd#cp_A4.003YearNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A4.003YearNoteMember_019f4274-b3fe-7568-bc75-22df8b1901ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A5.5030YearNoteMember_019f4274-b3fe-7476-b5de-f68922a64473" xlink:href="cp-20260630.xsd#cp_A5.5030YearNoteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A5.5030YearNoteMember_019f4274-b3fe-7476-b5de-f68922a64473" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A2YearCreditFacilityMember_019f4274-b3fe-7075-8fb9-85b7a0a3bc86" xlink:href="cp-20260630.xsd#cp_A2YearCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A2YearCreditFacilityMember_019f4274-b3fe-7075-8fb9-85b7a0a3bc86" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_A5YearCreditFacilityMember_019f4274-b3fe-7baa-934f-b7485bbe1140" xlink:href="cp-20260630.xsd#cp_A5YearCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_cp_A5YearCreditFacilityMember_019f4274-b3fe-7baa-934f-b7485bbe1140" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019f4274-b3fe-7f91-8b7c-60a7c8eb078e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f4274-b3fe-73c4-91ab-a646d00dffbe" xlink:to="loc_us-gaap_CommercialPaperMember_019f4274-b3fe-7f91-8b7c-60a7c8eb078e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f4274-b3fe-78fe-b645-73a1d27d35b6" 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_019f4274-b3fe-7e23-b5b9-1dab47e7ebc1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f4274-b3fe-78fe-b645-73a1d27d35b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-78fe-b645-73a1d27d35b6_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_019f4274-b3fe-78fe-b645-73a1d27d35b6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-78fe-b645-73a1d27d35b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-7854-ac2b-953a1280d9b1" 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_019f4274-b3fe-78fe-b645-73a1d27d35b6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-7854-ac2b-953a1280d9b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019f4274-b3fe-7fad-9c20-bee93f411c84" 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_019f4274-b3fe-7854-ac2b-953a1280d9b1" xlink:to="loc_us-gaap_SeniorNotesMember_019f4274-b3fe-7fad-9c20-bee93f411c84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019f4274-b3fe-73df-a243-9c8e4d1e45b3" 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_019f4274-b3fe-7854-ac2b-953a1280d9b1" xlink:to="loc_us-gaap_LineOfCreditMember_019f4274-b3fe-73df-a243-9c8e4d1e45b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_TheFacilityMember_019f4274-b3fe-72cc-8abd-5c3db811714a" xlink:href="cp-20260630.xsd#cp_TheFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-7854-ac2b-953a1280d9b1" xlink:to="loc_cp_TheFacilityMember_019f4274-b3fe-72cc-8abd-5c3db811714a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019f4274-b3fe-7628-9e56-b5037bdadef7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f4274-b3fe-7854-ac2b-953a1280d9b1" xlink:to="loc_us-gaap_UnsecuredDebtMember_019f4274-b3fe-7628-9e56-b5037bdadef7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f4274-b3fe-7478-8ef0-fc8f100cb4eb" 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_019f4274-b3fe-7e23-b5b9-1dab47e7ebc1" xlink:to="loc_us-gaap_CreditFacilityAxis_019f4274-b3fe-7478-8ef0-fc8f100cb4eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f4274-b3fe-7478-8ef0-fc8f100cb4eb_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_019f4274-b3fe-7478-8ef0-fc8f100cb4eb" xlink:to="loc_us-gaap_CreditFacilityDomain_019f4274-b3fe-7478-8ef0-fc8f100cb4eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f4274-b3fe-77e6-9a26-c82291654176" 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_019f4274-b3fe-7478-8ef0-fc8f100cb4eb" xlink:to="loc_us-gaap_CreditFacilityDomain_019f4274-b3fe-77e6-9a26-c82291654176" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019f4274-b3fe-7498-9308-e4e2a76a326f" 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_019f4274-b3fe-77e6-9a26-c82291654176" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019f4274-b3fe-7498-9308-e4e2a76a326f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_CommercialPaperProgramMember_019f4274-b3fe-72be-b93a-89ec4d4a5fe3" xlink:href="cp-20260630.xsd#cp_CommercialPaperProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f4274-b3fe-77e6-9a26-c82291654176" xlink:to="loc_cp_CommercialPaperProgramMember_019f4274-b3fe-72be-b93a-89ec4d4a5fe3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAmount_019f4274-b3fe-717c-b8e0-f6df46c23538" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExtinguishmentOfDebtAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAmount_019f4274-b3fe-717c-b8e0-f6df46c23538" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f4274-b3fe-756a-9706-184f891c9da0" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f4274-b3fe-756a-9706-184f891c9da0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_019f4274-b3fe-7a7c-9e8f-4271e3392c23" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_DebtInstrumentTerm_019f4274-b3fe-7a7c-9e8f-4271e3392c23" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019f4274-b3fe-72b0-9caf-686e4c87afa9" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019f4274-b3fe-72b0-9caf-686e4c87afa9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfUnsecuredDebt_019f4274-b3fe-7aed-9c67-dae3645ca33a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfUnsecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfUnsecuredDebt_019f4274-b3fe-7aed-9c67-dae3645ca33a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019f4274-b3fe-7b11-a066-8799316853e5" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019f4274-b3fe-7b11-a066-8799316853e5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f4274-b3fe-7efc-a9c1-84062c7bf4d9" 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_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f4274-b3fe-7efc-a9c1-84062c7bf4d9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaper_019f4274-b3fe-732d-b409-25e277f42c09" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaper"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_CommercialPaper_019f4274-b3fe-732d-b409-25e277f42c09" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_019f4274-b3fe-7750-88a7-d5c545ad2d88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f4274-b3fe-7b73-8435-17b092184562" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_019f4274-b3fe-7750-88a7-d5c545ad2d88" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/FinancialinstrumentsDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#FinancialinstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/FinancialinstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f4274-b3fe-7c81-ba51-fa5d5d65566a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_019f4274-b3fe-74f9-939b-96e6c7231d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f4274-b3fe-7c81-ba51-fa5d5d65566a" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_019f4274-b3fe-74f9-939b-96e6c7231d2a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019f4274-b3fe-7420-9c93-3f2962886be6" 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_ScheduleOfInvestmentsTable_019f4274-b3fe-74f9-939b-96e6c7231d2a" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019f4274-b3fe-7420-9c93-3f2962886be6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019f4274-b3fe-7420-9c93-3f2962886be6_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_019f4274-b3fe-7420-9c93-3f2962886be6" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019f4274-b3fe-7420-9c93-3f2962886be6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019f4274-b3fe-7996-a6b9-1437c4d2dc9c" 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_019f4274-b3fe-7420-9c93-3f2962886be6" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019f4274-b3fe-7996-a6b9-1437c4d2dc9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_019f4274-b3fe-78bf-a0e8-e3eebf3b2a12" 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_019f4274-b3fe-7996-a6b9-1437c4d2dc9c" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_019f4274-b3fe-78bf-a0e8-e3eebf3b2a12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_DebtAndFinanceLeaseLiabilitiesExcludingCommercialPaper_019f4274-b3fe-7b9b-8cb9-c27abc85475d" xlink:href="cp-20260630.xsd#cp_DebtAndFinanceLeaseLiabilitiesExcludingCommercialPaper"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f4274-b3fe-7c81-ba51-fa5d5d65566a" xlink:to="loc_cp_DebtAndFinanceLeaseLiabilitiesExcludingCommercialPaper_019f4274-b3fe-7b9b-8cb9-c27abc85475d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019f4274-b3fe-70ab-a432-e51ed14470b3" 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_ScheduleOfInvestmentsLineItems_019f4274-b3fe-7c81-ba51-fa5d5d65566a" xlink:to="loc_us-gaap_LongTermDebtFairValue_019f4274-b3fe-70ab-a432-e51ed14470b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f4274-b3fe-72d1-94a2-8db88aa03f39" 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_ScheduleOfInvestmentsLineItems_019f4274-b3fe-7c81-ba51-fa5d5d65566a" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_019f4274-b3fe-72d1-94a2-8db88aa03f39" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/SharerepurchasesNarrativeDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#SharerepurchasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/SharerepurchasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramLineItems_019f4274-b3fe-7b67-9e1c-79130c9f0ded" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramTable_019f4274-b3fe-7cae-aa52-fa8f4c8ce871" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019f4274-b3fe-7b67-9e1c-79130c9f0ded" xlink:to="loc_srt_ShareRepurchaseProgramTable_019f4274-b3fe-7cae-aa52-fa8f4c8ce871" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41" 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_srt_ShareRepurchaseProgramTable_019f4274-b3fe-7cae-aa52-fa8f4c8ce871" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41_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_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7e9e-b343-c8fdf7d8572f" 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_019f4274-b3fe-7cf3-a0bd-9aef0cb82c41" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7e9e-b343-c8fdf7d8572f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_February2026NormalCourseIssuerBidNCIBMember_019f4274-b3fe-7026-8b4e-473fd430e920" xlink:href="cp-20260630.xsd#cp_February2026NormalCourseIssuerBidNCIBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7e9e-b343-c8fdf7d8572f" xlink:to="loc_cp_February2026NormalCourseIssuerBidNCIBMember_019f4274-b3fe-7026-8b4e-473fd430e920" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_March2025NormalCourseIssuerBidNCIBMember_019f4274-b3fe-793b-b537-706088759f95" xlink:href="cp-20260630.xsd#cp_March2025NormalCourseIssuerBidNCIBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019f4274-b3fe-7e9e-b343-c8fdf7d8572f" xlink:to="loc_cp_March2025NormalCourseIssuerBidNCIBMember_019f4274-b3fe-793b-b537-706088759f95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_019f4274-b3fe-7b8f-b3e2-70358b453f1c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019f4274-b3fe-7b67-9e1c-79130c9f0ded" xlink:to="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_019f4274-b3fe-7b8f-b3e2-70358b453f1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f4274-b3fe-750c-a56c-8ad02cf466b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019f4274-b3fe-7b67-9e1c-79130c9f0ded" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f4274-b3fe-750c-a56c-8ad02cf466b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ShareRepurchaseProgramAccruedTaxLiability_019f4274-b3fe-752a-abf3-cc5fbf53b0f8" xlink:href="cp-20260630.xsd#cp_ShareRepurchaseProgramAccruedTaxLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramLineItems_019f4274-b3fe-7b67-9e1c-79130c9f0ded" xlink:to="loc_cp_ShareRepurchaseProgramAccruedTaxLiability_019f4274-b3fe-752a-abf3-cc5fbf53b0f8" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/PensionandotherbenefitsNarrativeDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#PensionandotherbenefitsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/PensionandotherbenefitsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f4274-b3fe-7987-a674-7d46a15261a8" 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_019f4274-b3fe-7e01-a928-a19438984946" 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_019f4274-b3fe-7987-a674-7d46a15261a8" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f4274-b3fe-7e01-a928-a19438984946" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019f4274-b3fe-7abc-aae1-ed41926bf71a" 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_019f4274-b3fe-7e01-a928-a19438984946" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019f4274-b3fe-7abc-aae1-ed41926bf71a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-7abc-aae1-ed41926bf71a_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_019f4274-b3fe-7abc-aae1-ed41926bf71a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-7abc-aae1-ed41926bf71a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-71b6-8458-a9847eb2a62e" 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_019f4274-b3fe-7abc-aae1-ed41926bf71a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-71b6-8458-a9847eb2a62e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019f4274-b3fe-77bb-8a68-38991693c783" 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_019f4274-b3fe-71b6-8458-a9847eb2a62e" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019f4274-b3fe-77bb-8a68-38991693c783" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_DefinedBenefitPlanPlanAssetsContributionsByEmployerNetOfRefunds_019f8004-8ad2-7351-86cb-d8dab4a91353" xlink:href="cp-20260630.xsd#cp_DefinedBenefitPlanPlanAssetsContributionsByEmployerNetOfRefunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f4274-b3fe-7987-a674-7d46a15261a8" xlink:to="loc_cp_DefinedBenefitPlanPlanAssetsContributionsByEmployerNetOfRefunds_019f8004-8ad2-7351-86cb-d8dab4a91353" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/PensionandotherbenefitsNetPeriodicBenefitCostforDBPensionPlansandOtherBenefitsDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#PensionandotherbenefitsNetPeriodicBenefitCostforDBPensionPlansandOtherBenefitsDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/PensionandotherbenefitsNetPeriodicBenefitCostforDBPensionPlansandOtherBenefitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f4274-b3fe-70ca-b071-3a9d53981203" 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_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f4274-b3fe-70ca-b071-3a9d53981203" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019f4274-b3fe-7dfd-8cbb-30d6f1214017" 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_019f4274-b3fe-70ca-b071-3a9d53981203" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019f4274-b3fe-7dfd-8cbb-30d6f1214017" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-7dfd-8cbb-30d6f1214017_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_019f4274-b3fe-7dfd-8cbb-30d6f1214017" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-7dfd-8cbb-30d6f1214017_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-73af-9573-7874aa3c417e" 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_019f4274-b3fe-7dfd-8cbb-30d6f1214017" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f4274-b3fe-73af-9573-7874aa3c417e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019f4274-b3fe-7bdf-8571-0629e1d83800" 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_019f4274-b3fe-73af-9573-7874aa3c417e" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019f4274-b3fe-7bdf-8571-0629e1d83800" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019f4274-b3fe-7fa3-b9a0-6c3a73ebee2a" 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_019f4274-b3fe-73af-9573-7874aa3c417e" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019f4274-b3fe-7fa3-b9a0-6c3a73ebee2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_019f4274-b3fe-75c5-a6b9-7853ae93189e" 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_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_019f4274-b3fe-75c5-a6b9-7853ae93189e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PensionAndOtherPostretirementBenefitExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:to="loc_us-gaap_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_019f4274-b3fe-70ba-be22-fe7c761b0b72" 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_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_019f4274-b3fe-70ba-be22-fe7c761b0b72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019f4274-b3fe-7370-a4ea-688df3a7e435" 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_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019f4274-b3fe-7370-a4ea-688df3a7e435" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019f4274-b3fe-708b-9b53-bb12f49d4ca8" 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_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019f4274-b3fe-708b-9b53-bb12f49d4ca8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019f4274-b3fe-7782-a0ed-be55acb907af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PensionAndOtherPostretirementBenefitExpenseAbstract_019f4274-b3fe-71ab-b27b-587caa0ed65f" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019f4274-b3fe-7782-a0ed-be55acb907af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_019f4274-b3fe-7a0e-99c9-e7456d76ecd6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:to="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_019f4274-b3fe-7a0e-99c9-e7456d76ecd6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019f4274-b3fe-7727-aa08-1d85dc42b7b8" 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_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_019f4274-b3fe-7e6f-bc3c-0fab81ba7165" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019f4274-b3fe-7727-aa08-1d85dc42b7b8" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/StockbasedcompensationNarrativeDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#StockbasedcompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/StockbasedcompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" 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_019f4274-b3fe-74a6-aaf3-fc1f5cef271b" 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_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f4274-b3fe-74a6-aaf3-fc1f5cef271b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f4274-b3fe-743e-aa47-40d2bb613307" 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_019f4274-b3fe-74a6-aaf3-fc1f5cef271b" xlink:to="loc_us-gaap_AwardTypeAxis_019f4274-b3fe-743e-aa47-40d2bb613307" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-743e-aa47-40d2bb613307_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_019f4274-b3fe-743e-aa47-40d2bb613307" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-743e-aa47-40d2bb613307_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-78a3-a18f-ec7af994546e" 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_019f4274-b3fe-743e-aa47-40d2bb613307" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-78a3-a18f-ec7af994546e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019f4274-b3fe-7ec1-969c-f093e7514d58" 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_019f4274-b3fe-78a3-a18f-ec7af994546e" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019f4274-b3fe-7ec1-969c-f093e7514d58" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019f4274-b3fe-7a4b-897a-f9bd9b90ad94" 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_019f4274-b3fe-78a3-a18f-ec7af994546e" xlink:to="loc_us-gaap_PerformanceSharesMember_019f4274-b3fe-7a4b-897a-f9bd9b90ad94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PerformanceDeferredShareUnitsMember_019f4274-b3fe-7590-83af-acca9277dc78" xlink:href="cp-20260630.xsd#cp_PerformanceDeferredShareUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-78a3-a18f-ec7af994546e" xlink:to="loc_cp_PerformanceDeferredShareUnitsMember_019f4274-b3fe-7590-83af-acca9277dc78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PSUsandPDSUsMember_019f4274-b3fe-715f-bad7-5a82118e0d35" xlink:href="cp-20260630.xsd#cp_PSUsandPDSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f4274-b3fe-78a3-a18f-ec7af994546e" xlink:to="loc_cp_PSUsandPDSUsMember_019f4274-b3fe-715f-bad7-5a82118e0d35" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e" 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_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f4274-b3fe-74a6-aaf3-fc1f5cef271b" xlink:to="loc_srt_RangeAxis_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e_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_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e" xlink:to="loc_srt_RangeMember_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f4274-b3fe-7ef8-a905-e56b98730757" 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_019f4274-b3fe-7c27-bd7f-4e8ac3981f7e" xlink:to="loc_srt_RangeMember_019f4274-b3fe-7ef8-a905-e56b98730757" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f4274-b3fe-7e34-af81-202028e2df18" 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_019f4274-b3fe-7ef8-a905-e56b98730757" xlink:to="loc_srt_MinimumMember_019f4274-b3fe-7e34-af81-202028e2df18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f4274-b3fe-763f-b920-4fbd680fbe40" 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_019f4274-b3fe-7ef8-a905-e56b98730757" xlink:to="loc_srt_MaximumMember_019f4274-b3fe-763f-b920-4fbd680fbe40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_019f4274-b3fe-7643-9a55-254c515a81ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f4274-b3fe-74a6-aaf3-fc1f5cef271b" xlink:to="loc_us-gaap_VestingAxis_019f4274-b3fe-7643-9a55-254c515a81ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019f4274-b3fe-7643-9a55-254c515a81ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_019f4274-b3fe-7643-9a55-254c515a81ae" xlink:to="loc_us-gaap_VestingDomain_019f4274-b3fe-7643-9a55-254c515a81ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019f4274-b3fe-74f9-8971-786d707aa3ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_019f4274-b3fe-7643-9a55-254c515a81ae" xlink:to="loc_us-gaap_VestingDomain_019f4274-b3fe-74f9-8971-786d707aa3ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019f4274-b3fe-79c5-82a9-342d98291c9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_019f4274-b3fe-74f9-8971-786d707aa3ee" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_019f4274-b3fe-79c5-82a9-342d98291c9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f4274-b3fe-7def-b6d7-46166d74f09c" 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_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f4274-b3fe-7def-b6d7-46166d74f09c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019f4274-b3fe-792c-9061-f1ab021dd479" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019f4274-b3fe-792c-9061-f1ab021dd479" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIssuedWeightedAveragePrice_019f4274-b3fe-7146-9dff-5ec4f353762e" xlink:href="cp-20260630.xsd#cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIssuedWeightedAveragePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIssuedWeightedAveragePrice_019f4274-b3fe-7146-9dff-5ec4f353762e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f4274-b3fe-792c-b80a-65b831e5520b" 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_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f4274-b3fe-792c-b80a-65b831e5520b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019f4274-b3fe-79e5-bece-e44ca538d9c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019f4274-b3fe-79e5-bece-e44ca538d9c1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross_019f4274-b3fe-705a-97dc-b18e3b326eec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross_019f4274-b3fe-705a-97dc-b18e3b326eec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f4274-b3fe-7cdf-8860-399144bd7648" 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f4274-b3fe-7cdf-8860-399144bd7648" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDateFairValue_019f4274-b3fe-7e16-b56b-d3cabcee0375" xlink:href="cp-20260630.xsd#cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDateFairValue_019f4274-b3fe-7e16-b56b-d3cabcee0375" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_NumberOfUnitsThatCanBeGrantedAsPercentageOfSharesAcquired_019f4274-b3fe-7a50-8459-238cd1093ead" xlink:href="cp-20260630.xsd#cp_NumberOfUnitsThatCanBeGrantedAsPercentageOfSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_cp_NumberOfUnitsThatCanBeGrantedAsPercentageOfSharesAcquired_019f4274-b3fe-7a50-8459-238cd1093ead" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019f4274-b3fe-7f38-8b15-d3951a35f849" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019f4274-b3fe-7f38-8b15-d3951a35f849" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_SharebasedCompensationArrangementbySharebasedPaymentAwardTradingDaysUsedtoCalculateAverageSharePrice_019f4274-b3fe-7b60-b858-adfab859862d" xlink:href="cp-20260630.xsd#cp_SharebasedCompensationArrangementbySharebasedPaymentAwardTradingDaysUsedtoCalculateAverageSharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_cp_SharebasedCompensationArrangementbySharebasedPaymentAwardTradingDaysUsedtoCalculateAverageSharePrice_019f4274-b3fe-7b60-b858-adfab859862d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid_019f4274-b3fe-7aa5-bd23-498cc518c278" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaid_019f4274-b3fe-7aa5-bd23-498cc518c278" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaidAssociatedShares_019f4274-b3fe-74ba-84f5-47dcf1f720e7" xlink:href="cp-20260630.xsd#cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaidAssociatedShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_cp_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsShareBasedLiabilitiesPaidAssociatedShares_019f4274-b3fe-74ba-84f5-47dcf1f720e7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f4274-b3fe-74c7-bc34-4da574bed397" 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_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f4274-b3fe-74c7-bc34-4da574bed397" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_019f4274-b3fe-72d5-850b-c4cd11bad2c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f4274-b3fe-766b-9f1e-77bbb1aebb01" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested_019f4274-b3fe-72d5-850b-c4cd11bad2c6" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.cpr.ca/role/ContingenciesDetails" xlink:type="simple" xlink:href="cp-20260630.xsd#ContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.cpr.ca/role/ContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_019f4274-b3fe-7605-acbe-16f16e24401e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_srt_LitigationCaseAxis_019f4274-b3fe-7605-acbe-16f16e24401e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-7605-acbe-16f16e24401e_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_019f4274-b3fe-7605-acbe-16f16e24401e" xlink:to="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-7605-acbe-16f16e24401e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-72ba-9b63-f0a743210bf2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_019f4274-b3fe-7605-acbe-16f16e24401e" xlink:to="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-72ba-9b63-f0a743210bf2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LacMeganticRailAccidentMember_019f4274-b3fe-7e8a-9519-3f15bf5a70af" xlink:href="cp-20260630.xsd#cp_LacMeganticRailAccidentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-72ba-9b63-f0a743210bf2" xlink:to="loc_cp_LacMeganticRailAccidentMember_019f4274-b3fe-7e8a-9519-3f15bf5a70af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_RemingtonDevelopmentCorporationLegalClaimMember_019f4274-b3fe-77b4-8ab3-eb235166a2d3" xlink:href="cp-20260630.xsd#cp_RemingtonDevelopmentCorporationLegalClaimMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_019f4274-b3fe-72ba-9b63-f0a743210bf2" xlink:to="loc_cp_RemingtonDevelopmentCorporationLegalClaimMember_019f4274-b3fe-77b4-8ab3-eb235166a2d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019f4274-b3fe-7322-bfa1-ac385e8bcd58" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_srt_CounterpartyNameAxis_019f4274-b3fe-7322-bfa1-ac385e8bcd58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-7322-bfa1-ac385e8bcd58_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019f4274-b3fe-7322-bfa1-ac385e8bcd58" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-7322-bfa1-ac385e8bcd58_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019f4274-b3fe-7322-bfa1-ac385e8bcd58" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_QuebecMinisterofSustainableDevelopmentandEnvironmentMember_019f4274-b3fe-7c2d-abeb-c8d0b3218105" xlink:href="cp-20260630.xsd#cp_QuebecMinisterofSustainableDevelopmentandEnvironmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_QuebecMinisterofSustainableDevelopmentandEnvironmentMember_019f4274-b3fe-7c2d-abeb-c8d0b3218105" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_QuebecAttorneyGeneralMember_019f4274-b3fe-72fd-8634-40c4a66cae99" xlink:href="cp-20260630.xsd#cp_QuebecAttorneyGeneralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_QuebecAttorneyGeneralMember_019f4274-b3fe-72fd-8634-40c4a66cae99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_InitialInsurerClaimantsMember_019f4274-b3fe-79e4-9d1d-0712c1562b59" xlink:href="cp-20260630.xsd#cp_InitialInsurerClaimantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_InitialInsurerClaimantsMember_019f4274-b3fe-79e4-9d1d-0712c1562b59" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_AdditionalInsurerClaimantsMember_019f4274-b3fe-766f-a053-e03b74dba436" xlink:href="cp-20260630.xsd#cp_AdditionalInsurerClaimantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_AdditionalInsurerClaimantsMember_019f4274-b3fe-766f-a053-e03b74dba436" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_PlaintiffMember_019f4274-b3fe-783a-960e-e439270b5b50" xlink:href="cp-20260630.xsd#cp_PlaintiffMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_PlaintiffMember_019f4274-b3fe-783a-960e-e439270b5b50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_MMARMember_019f4274-b3fe-7299-bfaf-cd02c6ac3b53" xlink:href="cp-20260630.xsd#cp_MMARMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_MMARMember_019f4274-b3fe-7299-bfaf-cd02c6ac3b53" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_TheWDTrusteeMember_019f4274-b3fe-7b9a-8287-4954238e5d4e" xlink:href="cp-20260630.xsd#cp_TheWDTrusteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_TheWDTrusteeMember_019f4274-b3fe-7b9a-8287-4954238e5d4e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_RemingtonDevelopmentCorporationMember_019f4274-b3fe-7bdf-8ea7-93f0d12cbd21" xlink:href="cp-20260630.xsd#cp_RemingtonDevelopmentCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f4274-b3fe-701c-b43c-425fd69551c4" xlink:to="loc_cp_RemingtonDevelopmentCorporationMember_019f4274-b3fe-7bdf-8ea7-93f0d12cbd21" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f4274-b3fe-7cfa-9488-053e385e5ed8" 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_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f4274-b3fe-7cfa-9488-053e385e5ed8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-7cfa-9488-053e385e5ed8_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_019f4274-b3fe-7cfa-9488-053e385e5ed8" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-7cfa-9488-053e385e5ed8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" 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_019f4274-b3fe-7cfa-9488-053e385e5ed8" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ClaimedLossorDamagesDuetoDerailmentMember_019f4274-b3fe-78b8-8604-f59a2695b143" xlink:href="cp-20260630.xsd#cp_ClaimedLossorDamagesDuetoDerailmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_ClaimedLossorDamagesDuetoDerailmentMember_019f4274-b3fe-78b8-8604-f59a2695b143" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_SubrogatedInsuranceClaimMember_019f4274-b3fe-7ccc-ae5f-75ec05c12fd7" xlink:href="cp-20260630.xsd#cp_SubrogatedInsuranceClaimMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_SubrogatedInsuranceClaimMember_019f4274-b3fe-7ccc-ae5f-75ec05c12fd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_DamagesforlossinbusinessvalueMember_019f4274-b3fe-74a8-866a-7159a47067ff" xlink:href="cp-20260630.xsd#cp_DamagesforlossinbusinessvalueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_DamagesforlossinbusinessvalueMember_019f4274-b3fe-74a8-866a-7159a47067ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LadingLossRecoveryMember_019f4274-b3fe-7040-9271-73f40b433390" xlink:href="cp-20260630.xsd#cp_LadingLossRecoveryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_LadingLossRecoveryMember_019f4274-b3fe-7040-9271-73f40b433390" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ReimbursementforsettlementpaidbyconsignorMember_019f4274-b3fe-7281-b491-df5204e3023b" xlink:href="cp-20260630.xsd#cp_ReimbursementforsettlementpaidbyconsignorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_ReimbursementforsettlementpaidbyconsignorMember_019f4274-b3fe-7281-b491-df5204e3023b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ReimbursementforsettlementpaidbyconsigneeMember_019f4274-b3fe-7b8f-bb32-96436d82a8d7" xlink:href="cp-20260630.xsd#cp_ReimbursementforsettlementpaidbyconsigneeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_ReimbursementforsettlementpaidbyconsigneeMember_019f4274-b3fe-7b8f-bb32-96436d82a8d7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_BreachOfContractMember_019f4274-b3fe-77cb-b318-234d91aecd46" xlink:href="cp-20260630.xsd#cp_BreachOfContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f4274-b3fe-77ca-bcc6-847cf1b3126a" xlink:to="loc_cp_BreachOfContractMember_019f4274-b3fe-77cb-b318-234d91aecd46" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019f4274-b3fe-7d91-bea3-58cb4d6823b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019f4274-b3fe-7d91-bea3-58cb4d6823b0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019f4274-b3fe-7d91-bea3-58cb4d6823b0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019f4274-b3fe-7d91-bea3-58cb4d6823b0" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019f4274-b3fe-7d91-bea3-58cb4d6823b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019f4274-b3fe-7448-8885-645c1e7c831d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019f4274-b3fe-7d91-bea3-58cb4d6823b0" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019f4274-b3fe-7448-8885-645c1e7c831d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_019f4274-b3fe-790b-8e38-9399019e0996" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019f4274-b3fe-7448-8885-645c1e7c831d" xlink:to="loc_us-gaap_ForeignCountryMember_019f4274-b3fe-790b-8e38-9399019e0996" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f4274-b3fe-7c50-9c9b-6cbdb1c94060" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f4274-b3fe-7c50-9c9b-6cbdb1c94060" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f4274-b3fe-7c50-9c9b-6cbdb1c94060_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f4274-b3fe-7c50-9c9b-6cbdb1c94060" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f4274-b3fe-7c50-9c9b-6cbdb1c94060_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f4274-b3fe-7719-b70c-0dbbb937929e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f4274-b3fe-7c50-9c9b-6cbdb1c94060" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f4274-b3fe-7719-b70c-0dbbb937929e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MexicanTaxAuthorityMember_019f4274-b3fe-74f1-87e9-42ef006c3217" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MexicanTaxAuthorityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f4274-b3fe-7719-b70c-0dbbb937929e" xlink:to="loc_us-gaap_MexicanTaxAuthorityMember_019f4274-b3fe-74f1-87e9-42ef006c3217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodAxis_019f4274-b3fe-7bf9-bea4-bd10fc2c3793" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_019f4274-b3fe-71e4-9e86-41cbbf1a9cac" xlink:to="loc_us-gaap_TaxPeriodAxis_019f4274-b3fe-7bf9-bea4-bd10fc2c3793" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodDomain_019f4274-b3fe-7bf9-bea4-bd10fc2c3793_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxPeriodAxis_019f4274-b3fe-7bf9-bea4-bd10fc2c3793" xlink:to="loc_us-gaap_TaxPeriodDomain_019f4274-b3fe-7bf9-bea4-bd10fc2c3793_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodDomain_019f4274-b3fe-7cba-bf77-10d57b5d2ebf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxPeriodAxis_019f4274-b3fe-7bf9-bea4-bd10fc2c3793" xlink:to="loc_us-gaap_TaxPeriodDomain_019f4274-b3fe-7cba-bf77-10d57b5d2ebf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxYear2014Member_019f4274-b3fe-7d3e-a0c8-4f7e767b6b1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxYear2014Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_019f4274-b3fe-7cba-bf77-10d57b5d2ebf" xlink:to="loc_us-gaap_TaxYear2014Member_019f4274-b3fe-7d3e-a0c8-4f7e767b6b1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_AmountofFundtobeDistributed_019f4274-b3fe-775c-94a6-5e1bb5b7334c" xlink:href="cp-20260630.xsd#cp_AmountofFundtobeDistributed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_AmountofFundtobeDistributed_019f4274-b3fe-775c-94a6-5e1bb5b7334c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_019f4274-b3fe-734e-9421-6426a8d88f87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_019f4274-b3fe-734e-9421-6426a8d88f87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LossContingencyDamagesSoughtPreviouslyValue_019f4274-b3fe-71bc-bf02-f2df344b5c1a" xlink:href="cp-20260630.xsd#cp_LossContingencyDamagesSoughtPreviouslyValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_LossContingencyDamagesSoughtPreviouslyValue_019f4274-b3fe-71bc-bf02-f2df344b5c1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_019f4274-b3fe-730b-a503-40fd68a358ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_019f4274-b3fe-730b-a503-40fd68a358ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019f4274-b3fe-7847-846b-b8e3a7db0e7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNumberOfPlaintiffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019f4274-b3fe-7847-846b-b8e3a7db0e7f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LossContingencyNumberOfOptedOutPlaintiffsOptedOut_019f4274-b3fe-7b05-9572-1e8628bc9ca7" xlink:href="cp-20260630.xsd#cp_LossContingencyNumberOfOptedOutPlaintiffsOptedOut"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_LossContingencyNumberOfOptedOutPlaintiffsOptedOut_019f4274-b3fe-7b05-9572-1e8628bc9ca7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LossContingencyAppealsNumberOfBankruptcyProceduralGrounds_019f4274-b3fe-7b34-b0f5-e48f2eead351" xlink:href="cp-20260630.xsd#cp_LossContingencyAppealsNumberOfBankruptcyProceduralGrounds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_LossContingencyAppealsNumberOfBankruptcyProceduralGrounds_019f4274-b3fe-7b34-b0f5-e48f2eead351" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesAwardedValue_019f4274-b3fe-727a-8d4e-899be15fe1ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyDamagesAwardedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_LossContingencyDamagesAwardedValue_019f4274-b3fe-727a-8d4e-899be15fe1ce" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_LossContingencyTotalEstimatedDamagesValue_019f4274-b3fe-7073-9eaa-19bbfb8db985" xlink:href="cp-20260630.xsd#cp_LossContingencyTotalEstimatedDamagesValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_LossContingencyTotalEstimatedDamagesValue_019f4274-b3fe-7073-9eaa-19bbfb8db985" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_019f4274-b3fe-7d45-b9d0-ab50df0f3903" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss_019f4274-b3fe-7d45-b9d0-ab50df0f3903" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019f4274-b3fe-7c37-ac0c-889aa0a3b6ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccrualForEnvironmentalLossContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019f4274-b3fe-7c37-ac0c-889aa0a3b6ee" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_cp_ExpectedTimePeriodForPaymentOfProvisionForEnvironmentalRemediation_019f4274-b3fe-7a4f-a92e-6ca38c8d87ee" xlink:href="cp-20260630.xsd#cp_ExpectedTimePeriodForPaymentOfProvisionForEnvironmentalRemediation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019f4274-b3fe-78be-803d-354ef71ed449" xlink:to="loc_cp_ExpectedTimePeriodForPaymentOfProvisionForEnvironmentalRemediation_019f4274-b3fe-7a4f-a92e-6ca38c8d87ee" xlink:type="arc" order="11"/>
  </link:definitionLink>
</link:linkbase>
