<SEC-DOCUMENT>0000846913-15-000039.txt : 20150409
<SEC-HEADER>0000846913-15-000039.hdr.sgml : 20150409
<ACCEPTANCE-DATETIME>20150409171208
ACCESSION NUMBER:		0000846913-15-000039
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150331
FILED AS OF DATE:		20150409
DATE AS OF CHANGE:		20150409

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAILEY RALPH E
		CENTRAL INDEX KEY:			0001246269

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33059
		FILM NUMBER:		15762045

	MAIL ADDRESS:	
		STREET 1:		695 E. MAIN STREET
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06901

	FORMER NAME:	
		FORMER CONFORMED NAME:	BILEY RALPH E
		DATE OF NAME CHANGE:	20030624
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_142861391892712.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-03-31</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001246269</rptOwnerCik>
            <rptOwnerName>BAILEY RALPH E</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>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1399617</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2919356</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Owned by Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Owned jointly with Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>245000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Family Trust</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares transferred by reporting person's spouse to a grantor retained annuity trust (&quot;Spouse's GRAT&quot;).</footnote>
        <footnote id="F2">Mr. Bailey has power of substitution over property in this trust but neither Mr. Bailey nor his spouse are beneficiaries of the trust and Mr. Bailey disclaims beneficial ownership of such shares.  This report should not be deemed admission that the reporting person is the beneficial owner of the shares in this trust for purposes of Section 16 or for any other purposes.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Ralph E. Bailey</signatureName>
        <signatureDate>2015-04-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
