<SEC-DOCUMENT>0001209191-22-031993.txt : 20220525
<SEC-HEADER>0001209191-22-031993.hdr.sgml : 20220525
<ACCEPTANCE-DATETIME>20220525195208
ACCESSION NUMBER:		0001209191-22-031993
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20220524
FILED AS OF DATE:		20220525
DATE AS OF CHANGE:		20220525

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			McDermott Charles Douglas
		CENTRAL INDEX KEY:			0001710696

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38692
		FILM NUMBER:		22964604

	MAIL ADDRESS:	
		STREET 1:		100 BEAVER STREET
		STREET 2:		SUITE 201
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Equillium, Inc.
		CENTRAL INDEX KEY:			0001746466
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				821554746
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2223 AVENIDA DE LA PLAYA
		STREET 2:		SUITE 105
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037
		BUSINESS PHONE:		(858) 412-5302

	MAIL ADDRESS:	
		STREET 1:		2223 AVENIDA DE LA PLAYA
		STREET 2:		SUITE 105
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-05-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001746466</issuerCik>
        <issuerName>Equillium, Inc.</issuerName>
        <issuerTradingSymbol>EQ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001710696</rptOwnerCik>
            <rptOwnerName>McDermott Charles Douglas</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2223 AVENIDA DE LA PLAYA, SUITE 105</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LA JOLLA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92037</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.59</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2022-05-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2032-05-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option vests in twelve equal monthly installments commencing on the grant date of May 24, 2022, provided that the option will, in any case, be fully vested on the date of the Issuer's annual meeting of stockholders following the grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jason A. Keyes, Attorney-in-Fact for Charles Douglas McDermott</signatureName>
        <signatureDate>2022-05-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
