<SEC-DOCUMENT>0001673985-21-000101.txt : 20210702
<SEC-HEADER>0001673985-21-000101.hdr.sgml : 20210702
<ACCEPTANCE-DATETIME>20210702165305
ACCESSION NUMBER:		0001673985-21-000101
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210630
FILED AS OF DATE:		20210702
DATE AS OF CHANGE:		20210702

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hughes Darrell K.
		CENTRAL INDEX KEY:			0001685371

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37774
		FILM NUMBER:		211070995

	MAIL ADDRESS:	
		STREET 1:		300 KIMBALL DRIVE, SUITE 101
		STREET 2:		C/O LEGAL DEPT.
		CITY:			PARSIPPANY
		STATE:			NJ
		ZIP:			07054

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AdvanSix Inc.
		CENTRAL INDEX KEY:			0001673985
		STANDARD INDUSTRIAL CLASSIFICATION:	PLASTICS, MATERIALS, SYNTH RESINS & NONVULCAN ELASTOMERS [2821]
		IRS NUMBER:				812525089
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		300 KIMBALL DRIVE
		STREET 2:		SUITE 101
		CITY:			PARSIPPANY
		STATE:			NJ
		ZIP:			07054
		BUSINESS PHONE:		(973) 526-1800

	MAIL ADDRESS:	
		STREET 1:		300 KIMBALL DRIVE
		STREET 2:		SUITE 101
		CITY:			PARSIPPANY
		STATE:			NJ
		ZIP:			07054
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_162525914601039.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-06-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001673985</issuerCik>
        <issuerName>AdvanSix Inc.</issuerName>
        <issuerTradingSymbol>ASIX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001685371</rptOwnerCik>
            <rptOwnerName>Hughes Darrell K.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>300 KIMBALL DRIVE, SUITE 101</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PARSIPPANY</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2021-06-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>264</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.86</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26405</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the allocation of deferred compensation to the reporting person's deferred stock unit fund account under the AdvanSix Inc. Deferred Compensation Plan. Each unit allocated under the stock unit fund represents the economic equivalent of one share of common stock. Units are paid out in shares of AdvanSix Inc. common stock upon distribution.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Achilles B. Kintiroglou for Darrell K. Hughes</signatureName>
        <signatureDate>2021-07-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
