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>0001933694</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001158324</issuerCik>
        <issuerName>COGENT COMMUNICATIONS HOLDINGS, INC.</issuerName>
        <secFileNumber>000-51829</secFileNumber>
        <issuerAddress>
          <com:street1>2450 N STREET, NW</com:street1>
          <com:city>WASHINGTON</com:city>
          <com:stateOrCountry>DC</com:stateOrCountry>
          <com:zipCode>20037</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>2022954200</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Howard Eve N</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Director</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>CITIGROUP GLOBAL MARKETS INC.</name>
          <address>
            <com:street1>388 Greenwich Street</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10013</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>1626</noOfUnitsSold>
        <aggregateMarketValue>133357.55</aggregateMarketValue>
        <noOfUnitsOutstanding>49024304</noOfUnitsOutstanding>
        <approxSaleDate>11/11/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>CITIGROUP GLOBAL MARKETS INC.</name>
          <address>
            <com:street1>CITIGROUP GLOBAL MARKETS INC.</com:street1>
            <com:street2>388 Greenwich Street</com:street2>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10013</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>1709</noOfUnitsSold>
        <aggregateMarketValue>140164.83</aggregateMarketValue>
        <noOfUnitsOutstanding>49024304</noOfUnitsOutstanding>
        <approxSaleDate>11/11/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>CITIGROUP GLOBAL MARKETS INC.</name>
          <address>
            <com:street1>CITIGROUP GLOBAL MARKETS INC.</com:street1>
            <com:street2>388 Greenwich Street</com:street2>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10013</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>165</noOfUnitsSold>
        <aggregateMarketValue>13532.59</aggregateMarketValue>
        <noOfUnitsOutstanding>49024304</noOfUnitsOutstanding>
        <approxSaleDate>11/11/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>10/06/2022</acquiredDate>
        <natureOfAcquisitionTransaction>Compensation for Board Services</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1626</amountOfSecuritiesAcquired>
        <paymentDate>10/06/2022</paymentDate>
        <natureOfPayment>Compensation for Board Services</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>01/04/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Compensation for Board Services</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1709</amountOfSecuritiesAcquired>
        <paymentDate>01/04/2023</paymentDate>
        <natureOfPayment>Compensation for Board Services</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>04/05/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Compensation for Board Services</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>165</amountOfSecuritiesAcquired>
        <paymentDate>04/05/2023</paymentDate>
        <natureOfPayment>Compensation for Board Services</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>11/14/2024</noticeDate>
        <signature>/s/ Aegis J. Frumento as a duly authorized representative of Citigroup Global Markets Inc., as attorney-in-fact for the named Filer</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 5620}]
text: 144
  0001933694
  XXXXXXXX
  LIVE
  0001158324
  COGENT COMMUNICATIONS HOLDINGS, INC.
  000-51829
  2450 N STREET, NW
  WASHINGTON
  DC
  20037
  2022954200
  Howard Eve N
  Director
  Common
  CITIGROUP GLOBAL MARKETS INC.
  388 Greenwich Street
  New York
  NY
  10013
  1626
  133357.55
  49024304
  11/11/2024
  NASDAQ
  Common
  CITIGROUP GLOBAL MARKETS INC.
  CITIGROUP GLOBAL MARKETS INC.
  388 Greenwich Street
  New York
  NY
  10013
  1709
  140164.83
  49024304
  11/11/2024
  NASDAQ
  Common
  CITIGROUP GLOBAL MARKETS INC.
  CITIGROUP GLOBAL MARKETS INC.
  388 Greenwich Street
  New York
  NY
  10013
  165
  13532.59
  49024304
  11/11/2024
  NASDAQ
  Common
  10/06/2022
  Compensation for Board Services
  Issuer
  N
  1626
  10/06/2022
  Compensation for Board Services
  Common
  01/04/2023
  Compensation for Board Services
  Issuer
  N
  1709
  01/04/2023
  Compensation for Board Services
  Common
  04/05/2023
  Compensation for Board Services
  Issuer
  N
  165
  04/05/2023
  Compensation for Board Services
  Y
  11/14/2024
  /s/ Aegis J. Frumento as a duly authorized representative of Citigroup Global Markets Inc., as attorney-in-fact for the named Filer