<SEC-DOCUMENT>0001387467-21-000066.txt : 20210913
<SEC-HEADER>0001387467-21-000066.hdr.sgml : 20210913
<ACCEPTANCE-DATETIME>20210913194813
ACCESSION NUMBER:		0001387467-21-000066
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210910
FILED AS OF DATE:		20210913
DATE AS OF CHANGE:		20210913

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Xue Bing
		CENTRAL INDEX KEY:			0001787488

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34717
		FILM NUMBER:		211250902

	MAIL ADDRESS:	
		STREET 1:		475 OAKMEAD PARKWAY
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALPHA & OMEGA SEMICONDUCTOR Ltd
		CENTRAL INDEX KEY:			0001387467
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		475 OAKMEAD PARKWAY
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085
		BUSINESS PHONE:		408-830-9742

	MAIL ADDRESS:	
		STREET 1:		475 OAKMEAD PARKWAY
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			94085

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALPHA & OMEGA SEMICONDUCTOR LTD
		DATE OF NAME CHANGE:	20070123
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_163157687865404.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001387467</issuerCik>
        <issuerName>ALPHA &amp; OMEGA SEMICONDUCTOR Ltd</issuerName>
        <issuerTradingSymbol>AOSL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001787488</rptOwnerCik>
            <rptOwnerName>Xue Bing</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>475 OAKMEAD PKWY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SUNNYVALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94085</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP-WW Sales &amp; Bus Development</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Share</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1492</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.63</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>53707</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sales were effected pursuant to a Rule 10b5-1 trading plan adopted previously by the Reporting Person.</footnote>
        <footnote id="F2">The price reported in Column 4 is the exact price at which all shares were sold.</footnote>
        <footnote id="F3">Includes an aggregate of 34,750 shares subject to Restricted Share Unit awards (RSU) granted on March 15, 2018, March 15, 2019, March 16, 2020, March 15, 2021, and August 12, 2021 which will be issued as such units vest in accordance with their terms, and excludes (a) 15,000 unvested common shares subject to the PSU granted on March 15, 2021, which may become vested upon achievement of certain corporate performance goals in the future and (b) 3,750 unvested common shares subject to the 2018 PSU which may be vested upon satisfaction of service-based vesting conditions by the Reporting Person.</footnote>
        <footnote id="F4">Includes 9,000 unvested common shares subject to the 2020 PSU granted on March 16, 2020 which may be vested upon satisfaction of service-based vesting conditions by the Reporting Person.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Yanbing Hong, attoryney-in-fact for Bing Xue</signatureName>
        <signatureDate>2021-09-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
