<SEC-DOCUMENT>0000846913-17-000075.txt : 20170906
<SEC-HEADER>0000846913-17-000075.hdr.sgml : 20170906
<ACCEPTANCE-DATETIME>20170906163440
ACCESSION NUMBER:		0000846913-17-000075
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170901
FILED AS OF DATE:		20170906
DATE AS OF CHANGE:		20170906

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Collins David S
		CENTRAL INDEX KEY:			0001497600

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33059
		FILM NUMBER:		171071733

	MAIL ADDRESS:	
		STREET 1:		C/O FUEL TECH
		STREET 2:		27601 BELLA VISTA PARKWAY
		CITY:			WARRENVILLE
		STATE:			IL
		ZIP:			60555

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FUEL TECH, INC.
		CENTRAL INDEX KEY:			0000846913
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
		IRS NUMBER:				205657551
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		27601 BELLA VISTA PARKWAY
		CITY:			WARRENVILLE
		STATE:			IL
		ZIP:			60555
		BUSINESS PHONE:		6308454433

	MAIL ADDRESS:	
		STREET 1:		27601 BELLA VISTA PARKWAY
		CITY:			WARRENVILLE
		STATE:			IL
		ZIP:			60555

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FUEL TECH N V
		DATE OF NAME CHANGE:	19930510
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_150473006682151.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-09-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000846913</issuerCik>
        <issuerName>FUEL TECH, INC.</issuerName>
        <issuerTradingSymbol>FTEK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001497600</rptOwnerCik>
            <rptOwnerName>Collins David S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FUEL TECH</rptOwnerStreet1>
            <rptOwnerStreet2>27601 BELLA VISTA PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>WARRENVILLE</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60555</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>79998</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.791</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average share price.  The shares were sold in multiple transactions at prices ranging from $0.704 to $0.903, inclusive.  The reporting person undertakes to provide to any security holder of Fuel Tech, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>David S. Collins</signatureName>
        <signatureDate>2017-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
