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                    <ccc>XXXXXXXX</ccc>
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            <liveTestFlag>LIVE</liveTestFlag>



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            <secFileNumber>001-36332</secFileNumber>
            <issuerAddress>
                <ns2:street1>131 Hartwell Avenue</ns2:street1>
                <ns2:street2>Suite 320</ns2:street2>
                <ns2:city>Lexington</ns2:city>
                <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                <ns2:zipCode>02421</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(781) 761-4904</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>STEPHEN G. MACHATHA</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
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            <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>
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            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>11537</noOfUnitsSold>
            <aggregateMarketValue>36501.91</aggregateMarketValue>
            <noOfUnitsOutstanding>58895768</noOfUnitsOutstanding>
            <approxSaleDate>03/12/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
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        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/30/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
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            <paymentDate>06/30/2019</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
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            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>2067</amountOfSecuritiesAcquired>
            <paymentDate>06/30/2018</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/31/2017</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
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            <amountOfSecuritiesAcquired>2933</amountOfSecuritiesAcquired>
            <paymentDate>12/31/2017</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/31/2018</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1308</amountOfSecuritiesAcquired>
            <paymentDate>12/31/2018</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/30/2020</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>450</amountOfSecuritiesAcquired>
            <paymentDate>06/30/2020</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/30/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1802</amountOfSecuritiesAcquired>
            <paymentDate>06/30/2021</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>12/31/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Employee Stock Purchase Plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>140</amountOfSecuritiesAcquired>
            <paymentDate>12/31/2019</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>STEPHEN G. MACHATHA</name>
                <address>
                    <ns2:street1>131 Hartwell Avenue</ns2:street1>
                    <ns2:street2>Suite 320</ns2:street2>
                    <ns2:city>Lexington</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02421</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/11/2024</saleDate>
            <amountOfSecuritiesSold>18231</amountOfSecuritiesSold>
            <grossProceeds>62102.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>03/12/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Stephen Gitu Machatha</signature>
        </noticeSignature>
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144
0001836354
XXXXXXXX
LIVE
0001341235
ALDEYRA THERAPEUTICS, INC.
001-36332
131 Hartwell Avenue
Suite 320
Lexington
MA
02421
(781) 761-4904
STEPHEN G. MACHATHA
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
11537
36501.91
58895768
03/12/2024
NASDAQ
Common
06/30/2019
Employee Stock Purchase Plan
Issuer
N
2837
06/30/2019
Cash
Common
06/30/2018
Employee Stock Purchase Plan
Issuer
N
2067
06/30/2018
Cash
Common
12/31/2017
Employee Stock Purchase Plan
Issuer
N
2933
12/31/2017
Cash
Common
12/31/2018
Employee Stock Purchase Plan
Issuer
N
1308
12/31/2018
Cash
Common
06/30/2020
Employee Stock Purchase Plan
Issuer
N
450
06/30/2020
Cash
Common
06/30/2021
Employee Stock Purchase Plan
Issuer
N
1802
06/30/2021
Cash
Common
12/31/2019
Employee Stock Purchase Plan
Issuer
N
140
12/31/2019
Cash
N
STEPHEN G. MACHATHA
131 Hartwell Avenue
Suite 320
Lexington
MA
02421
Common
03/11/2024
18231
62102.00
03/12/2024
/s/ Stephen Gitu Machatha