content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001283535</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001582313</issuerCik>
        <issuerName>Xenon Pharmaceuticals Inc.</issuerName>
        <secFileNumber>001-36687</secFileNumber>
        <issuerAddress>
          <com:street1>200 - 3650 GILMORE WAY</com:street1>
          <com:city>BURNABY</com:city>
          <com:stateOrCountry>A1</com:stateOrCountry>
          <com:zipCode>V5G 48W</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>(604) 484-3300</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>PATOU GARY</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Director</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Fidelity Brokerage Services LLC</name>
          <address>
            <com:street1>245 Summer Street</com:street1>
            <com:city>Boston</com:city>
            <com:stateOrCountry>MA</com:stateOrCountry>
            <com:zipCode>02110</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>7598</noOfUnitsSold>
        <aggregateMarketValue>307073.17</aggregateMarketValue>
        <noOfUnitsOutstanding>65429711</noOfUnitsOutstanding>
        <approxSaleDate>12/14/2023</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>08/10/2017</acquiredDate>
        <natureOfAcquisitionTransaction>Open Market Buy</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Open Market</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>7500</amountOfSecuritiesAcquired>
        <paymentDate>08/10/2017</paymentDate>
        <natureOfPayment>Cash/Check</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>08/08/2017</acquiredDate>
        <natureOfAcquisitionTransaction>Open Market Buy</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Open Market</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>98</amountOfSecuritiesAcquired>
        <paymentDate>08/08/2017</paymentDate>
        <natureOfPayment>Cash/Check</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Patou Family Trust</name>
          <address>
            <com:street1>200-3650 Gilmore Way</com:street1>
            <com:city>Burnaby</com:city>
            <com:stateOrCountry>A1</com:stateOrCountry>
            <com:zipCode>V5G4W8</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Xenon Pharmaceuticals Inc.</securitiesClassTitle>
        <saleDate>12/13/2023</saleDate>
        <amountOfSecuritiesSold>11380</amountOfSecuritiesSold>
        <grossProceeds>447085.91</grossProceeds>
      </securitiesSoldInPast3Months>
      <remarks>Shares will be sold out of the following account: Patou Family Trust</remarks>
      <noticeSignature>
        <noticeDate>12/14/2023</noticeDate>
        <signature>/s/ Christian Nasser as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Gary Patou</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4061}]
text: 144
  0001283535
  XXXXXXXX
  LIVE
  0001582313
  Xenon Pharmaceuticals Inc.
  001-36687
  200 - 3650 GILMORE WAY
  BURNABY
  A1
  V5G 48W
  (604) 484-3300
  PATOU GARY
  Director
  Common
  Fidelity Brokerage Services LLC
  245 Summer Street
  Boston
  MA
  02110
  7598
  307073.17
  65429711
  12/14/2023
  NASDAQ
  Common
  08/10/2017
  Open Market Buy
  Open Market
  N
  7500
  08/10/2017
  Cash/Check
  Common
  08/08/2017
  Open Market Buy
  Open Market
  N
  98
  08/08/2017
  Cash/Check
  N
  Patou Family Trust
  200-3650 Gilmore Way
  Burnaby
  A1
  V5G4W8
  Xenon Pharmaceuticals Inc.
  12/13/2023
  11380
  447085.91
  Shares will be sold out of the following account: Patou Family Trust
  12/14/2023
  /s/ Christian Nasser as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Gary Patou