    <SEC-DOCUMENT>0001193125-18-139235-index.html : 20180427
    <SEC-HEADER>0001193125-18-139235.hdr.sgml : 20180427
    <ACCEPTANCE-DATETIME>20180427170102
    ACCESSION NUMBER:		0001193125-18-139235
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		3
    FILED AS OF DATE:		20180427
    DATE AS OF CHANGE:		20180427
    EFFECTIVENESS DATE:		20180427

    FILER:

    	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

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-35667
    		FILM NUMBER:		18785274

    	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>DEFA14A
    <SEQUENCE>1
    <FILENAME>d576619ddefa14a.htm
    <DESCRIPTION>DEFINITIVE ADDITIONAL MATERIALS
    <TEXT>
    Document 1 - file: d576619ddefa14a.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>g576619pic01.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: g576619pic01.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>g576619pic02.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: g576619pic02.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>