<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001575229</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001110803</issuerCik>
            <issuerName>ILLUMINA INC</issuerName>
            <secFileNumber>001-35406</secFileNumber>
            <issuerAddress>
                <ns2:street1>5200 Illumina Way</ns2:street1>
                <ns2:city>San Diego</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>92122</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>8582024500</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>CHARLES E. DADSWELL TRUST U/A/D 02/12/2021</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>4948</noOfUnitsSold>
            <aggregateMarketValue>720131.92</aggregateMarketValue>
            <noOfUnitsOutstanding>159300000</noOfUnitsOutstanding>
            <approxSaleDate>10/14/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/01/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>53</amountOfSecuritiesAcquired>
            <paymentDate>08/01/2022</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/05/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>4895</amountOfSecuritiesAcquired>
            <paymentDate>11/05/2021</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for CHARLES E DADSWELL TTEECHARLES DADSWELL TRUST U/A DTD02/12/2021</name>
                <address>
                    <ns2:street1>5200 Illumina Way</ns2:street1>
                    <ns2:city>San Diego</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>92122</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>09/13/2024</saleDate>
            <amountOfSecuritiesSold>989</amountOfSecuritiesSold>
            <grossProceeds>125553.55</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for CHARLES E DADSWELL TTEECHARLES DADSWELL TRUST U/A DTD02/12/2021</name>
                <address>
                    <ns2:street1>5200 Illumina Way</ns2:street1>
                    <ns2:city>San Diego</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>92122</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>08/15/2024</saleDate>
            <amountOfSecuritiesSold>989</amountOfSecuritiesSold>
            <grossProceeds>122200.84</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>Sales that were executed on October 14, 2024 are being reported on this Form 144 filed on October 15, 2024 given the EDGAR system was not accepting filings on October 14, 2024 in observance of the federal holiday.
The securities to be sold were acquired upon the vesting of restricted stock units and performance stock units during the period of 11/05/2021 through 11/05/2023.
</remarks>
        <noticeSignature>
            <noticeDate>10/14/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>05/16/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Charles E. Dadswell</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 5827}]
144
0001575229
XXXXXXXX
LIVE
0001110803
ILLUMINA INC
001-35406
5200 Illumina Way
San Diego
CA
92122
8582024500
CHARLES E. DADSWELL TRUST U/A/D 02/12/2021
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
4948
720131.92
159300000
10/14/2024
NASDAQ
Common
08/01/2022
Employee Stock Purchase Plan
Issuer
N
53
08/01/2022
Cash
Common
11/05/2021
Restricted Stock Units
Issuer
N
4895
11/05/2021
N/A
N
10b5-1 Sales for CHARLES E DADSWELL TTEECHARLES DADSWELL TRUST U/A DTD02/12/2021
5200 Illumina Way
San Diego
CA
92122
Common
09/13/2024
989
125553.55
10b5-1 Sales for CHARLES E DADSWELL TTEECHARLES DADSWELL TRUST U/A DTD02/12/2021
5200 Illumina Way
San Diego
CA
92122
Common
08/15/2024
989
122200.84
Sales that were executed on October 14, 2024 are being reported on this Form 144 filed on October 15, 2024 given the EDGAR system was not accepting filings on October 14, 2024 in observance of the federal holiday.
The securities to be sold were acquired upon the vesting of restricted stock units and performance stock units during the period of 11/05/2021 through 11/05/2023.
10/14/2024
05/16/2024
/s/ Charles E. Dadswell