<?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>0001967207</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0001859690</issuerCik>
      <issuerName>Arqit Quantum Inc.</issuerName>
      <secFileNumber>001-40777</secFileNumber>
      <issuerAddress>
        <com:street1>NOVA NORTH</com:street1>
        <com:street2>7 FLOOR, 11 BRESSENDEN PLACE</com:street2>
        <com:city>LONDON</com:city>
        <com:stateOrCountry>X0</com:stateOrCountry>
        <com:zipCode>SW1E 5BY</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>44 203 91 70155</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Bestwick David</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Fidelity Brokerage Services LLC</name>
        <address>
          <com:street1>900 Salem Street</com:street1>
          <com:city>Smithfield</com:city>
          <com:stateOrCountry>RI</com:stateOrCountry>
          <com:zipCode>02917</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>2934</noOfUnitsSold>
      <aggregateMarketValue>3798.06</aggregateMarketValue>
      <noOfUnitsOutstanding>121926166</noOfUnitsOutstanding>
      <approxSaleDate>08/02/2023</approxSaleDate>
      <securitiesExchangeName>NYSE</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>08/01/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2934</amountOfSecuritiesAcquired>
      <paymentDate>08/01/2023</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>David Bestwick</name>
        <address>
          <com:street1>Nova North</com:street1>
          <com:street2>7 Floor, 11 Bressenden Place</com:street2>
          <com:city>London</com:city>
          <com:stateOrCountry>X0</com:stateOrCountry>
          <com:zipCode>SW1E 5BY</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>06/14/2023</saleDate>
      <amountOfSecuritiesSold>2731</amountOfSecuritiesSold>
      <grossProceeds>3846.07</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>David Bestwick</name>
        <address>
          <com:street1>Nova North</com:street1>
          <com:street2>7 Floor, 11 Bressenden Place</com:street2>
          <com:city>London</com:city>
          <com:stateOrCountry>X0</com:stateOrCountry>
          <com:zipCode>SW1E 5BY</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>07/03/2023</saleDate>
      <amountOfSecuritiesSold>3777</amountOfSecuritiesSold>
      <grossProceeds>4562.99</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>08/02/2023</noticeDate>
      <signature>/s/ Gary Redman, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for David Bestwick</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4164}]
144
0001967207
XXXXXXXX
LIVE
0001859690
Arqit Quantum Inc.
001-40777
NOVA NORTH
7 FLOOR, 11 BRESSENDEN PLACE
LONDON
X0
SW1E 5BY
44 203 91 70155
Bestwick David
Officer
Common
Fidelity Brokerage Services LLC
900 Salem Street
Smithfield
RI
02917
2934
3798.06
121926166
08/02/2023
NYSE
Common
08/01/2023
Restricted Stock Vesting
Issuer
N
2934
08/01/2023
Compensation
N
David Bestwick
Nova North
7 Floor, 11 Bressenden Place
London
X0
SW1E 5BY
Common
06/14/2023
2731
3846.07
David Bestwick
Nova North
7 Floor, 11 Bressenden Place
London
X0
SW1E 5BY
Common
07/03/2023
3777
4562.99
08/02/2023
/s/ Gary Redman, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for David Bestwick