<SEC-DOCUMENT>0001280263-21-000072.txt : 20210902
<SEC-HEADER>0001280263-21-000072.hdr.sgml : 20210902
<ACCEPTANCE-DATETIME>20210902165746
ACCESSION NUMBER:		0001280263-21-000072
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210901
FILED AS OF DATE:		20210902
DATE AS OF CHANGE:		20210902

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hu Chenming
		CENTRAL INDEX KEY:			0001316320

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35667
		FILM NUMBER:		211233993

	MAIL ADDRESS:	
		STREET 1:		2060 PEBBLE DRIVE
		CITY:			ALAMO
		STATE:			CA
		ZIP:			94507

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMBARELLA INC
		CENTRAL INDEX KEY:			0001280263
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				980459628
		FISCAL YEAR END:			0131

	BUSINESS ADDRESS:	
		STREET 1:		3101 JAY STREET
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
		BUSINESS PHONE:		408-734-8888

	MAIL ADDRESS:	
		STREET 1:		3101 JAY STREET
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001280263</issuerCik>
        <issuerName>AMBARELLA INC</issuerName>
        <issuerTradingSymbol>AMBA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001316320</rptOwnerCik>
            <rptOwnerName>Hu Chenming</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3101 JAY STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>120.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16953</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on December 11, 2020.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: /s/ Michael Morehead, Attorney-in-Fact For: Chenming Hu</signatureName>
        <signatureDate>2021-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>