<SEC-DOCUMENT>0001673985-18-000085.txt : 20180709
<SEC-HEADER>0001673985-18-000085.hdr.sgml : 20180709
<ACCEPTANCE-DATETIME>20180709161607
ACCESSION NUMBER:		0001673985-18-000085
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180709
FILED AS OF DATE:		20180709
DATE AS OF CHANGE:		20180709

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Marberry Michael
		CENTRAL INDEX KEY:			0001557769

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37774
		FILM NUMBER:		18944867

	MAIL ADDRESS:	
		STREET 1:		3050 SPRUCE STREET
		CITY:			ST. LOUIS
		STATE:			MO
		ZIP:			63103

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_153116734695499.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-07-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001557769</rptOwnerCik>
            <rptOwnerName>Marberry Michael</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>2018-07-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>665</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>37.82</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26245</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The purchases reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 15, 2017.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $37.57 to $37.84, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote to this Form 4.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ John M. Quitmeyer for Michael L. Marberry</signatureName>
        <signatureDate>2018-07-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
