<SEC-DOCUMENT>0001589526-18-000010.txt : 20180105
<SEC-HEADER>0001589526-18-000010.hdr.sgml : 20180105
<ACCEPTANCE-DATETIME>20180105115402
ACCESSION NUMBER:		0001589526-18-000010
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180103
FILED AS OF DATE:		20180105
DATE AS OF CHANGE:		20180105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Tighe Phillip
		CENTRAL INDEX KEY:			0001632684

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36267
		FILM NUMBER:		18512626

	MAIL ADDRESS:	
		STREET 1:		C/O BLUE BIRD CORPORATION
		STREET 2:		402 BLUE BIRD BOULEVARD
		CITY:			FORT VALLEY
		STATE:			GA
		ZIP:			31030

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Blue Bird Corp
		CENTRAL INDEX KEY:			0001589526
		STANDARD INDUSTRIAL CLASSIFICATION:	TRUCK & BUS BODIES [3713]
		IRS NUMBER:				463891989
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		402 BLUE BIRD BOULEVARD
		CITY:			FORT VALLEY
		STATE:			GA
		ZIP:			31030
		BUSINESS PHONE:		478-822-2801

	MAIL ADDRESS:	
		STREET 1:		402 BLUE BIRD BOULEVARD
		CITY:			FORT VALLEY
		STATE:			GA
		ZIP:			31030

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Hennessy Capital Acquisition Corp.
		DATE OF NAME CHANGE:	20131017
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151517122860169.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-01-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001589526</issuerCik>
        <issuerName>Blue Bird Corp</issuerName>
        <issuerTradingSymbol>BLBD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001632684</rptOwnerCik>
            <rptOwnerName>Tighe Phillip</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BLUE BIRD CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>402 BLUE BIRD BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>FORT VALLEY</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>31030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2018-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>966</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>102024</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2018-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2583</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>99441</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6860</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2018-01-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2027-01-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6860.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6860</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On January 3, 2017, the reporting person was granted an option to purchase 23,574 shares of common stock, which vests over a three year period in equal installments based on satisfaction of certain performance criteria for each of the applicable fiscal years.  The performance criteria for fiscal 2017 was partially met, resulting in the vesting of the option for 6,860 shares.</footnote>
        <footnote id="F2">Reflects an adjustment for previously reported options which had not yet vested or met performance criteria.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Paul Yousif as attorney-in-fact</signatureName>
        <signatureDate>2018-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
