<?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>0001967068</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>Feenan Paul</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>18391</noOfUnitsSold>
      <aggregateMarketValue>22218.18</aggregateMarketValue>
      <noOfUnitsOutstanding>121926166</noOfUnitsOutstanding>
      <approxSaleDate>07/03/2023</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>06/30/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>18391</amountOfSecuritiesAcquired>
      <paymentDate>06/30/2023</paymentDate>
      <natureOfPayment>Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Paul Feenan</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>04/03/2023</saleDate>
      <amountOfSecuritiesSold>17318</amountOfSecuritiesSold>
      <grossProceeds>22016.38</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Paul Feenan</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>06/15/2023</saleDate>
      <amountOfSecuritiesSold>2878</amountOfSecuritiesSold>
      <grossProceeds>3920.41</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>07/03/2023</noticeDate>
      <signature>/s/ Griffin Cain, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Paul Feenan</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4160}]
144
0001967068
XXXXXXXX
LIVE
0001859690
Arqit Quantum Inc.
001-40777
NOVA NORTH
7 FLOOR, 11 BRESSENDEN PLACE
LONDON
X0
SW1E 5BY
44 203 91 70155
Feenan Paul
Officer
Common
Fidelity Brokerage Services LLC
900 Salem Street
Smithfield
RI
02917
18391
22218.18
121926166
07/03/2023
NASDAQ
Common
06/30/2023
Restricted Stock Vesting
Issuer
N
18391
06/30/2023
Compensation
N
Paul Feenan
Nova North
7 Floor, 11 Bressenden Place
London
X0
SW1E 5BY
Common
04/03/2023
17318
22016.38
Paul Feenan
Nova North
7 Floor, 11 Bressenden Place
London
X0
SW1E 5BY
Common
06/15/2023
2878
3920.41
07/03/2023
/s/ Griffin Cain, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Paul Feenan