As filed with the Securities and Exchange Commission on March 29, 2019

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

Under

The Securities Act of 1933

Ambarella, Inc.

(Exact name of Registrant as specified in its charter)

3101 Jay Street

Santa Clara, CA 95054

(Address of principal executive offices, including zip code)

2012 Equity Incentive Plan

2012 Employee Stock Purchase Plan

(Full title of the plan)

Feng-Ming Wang

Chief Executive Officer

c/o Ambarella Corporation

3101 Jay Street

Santa Clara, CA 95054

(Name and address of agent for service)

(408) 734-8888

(Telephone number, including area code, of agent for service)

Copies to:

Larry W. Sonsini

Herbert P. Fockler

Wilson Sonsini Goodrich & Rosati, P.C.

650 Page Mill Road

Palo Alto, California 94304

(650) 493-9300

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” or “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

PART II

INFORMATION REQUIRED IN REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

Ambarella, Inc. (the “Registrant”) hereby incorporates by reference into this Registration Statement the following documents:

(1) The Registrant’s Annual Report on Form 10-K for the fiscal year ended January 31, 2019, filed with the Commission on March 29, 2019 pursuant to Section 13(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”);

(2) All other reports filed with the Commission pursuant to Sections 13(a) or 15(d) of the Exchange Act since the end of the fiscal year covered by the Registrant’s Annual Report referred to in (1) above; and

(3) The description of the Registrant’s ordinary shares contained in the Company’s Registration Statement on Form 8-A (File No. 001-35667) filed with the Commission on September 26, 2012, pursuant to Section 12(b) of the Exchange Act, including any amendment or report filed for the purpose of updating such description.

All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act on or after the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement that indicates that all securities offered have been sold or that deregisters all securities then remaining unsold shall be deemed to be incorporated by reference in this Registration Statement and to be part hereof from the date of filing of such documents; provided, however, that documents or information deemed to have been furnished and not filed in accordance with the rules of the Commission shall not be deemed incorporated by reference into this Registration Statement. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any subsequently filed document which also is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

Item 4. Description of Securities.

Not applicable.

Item 5. Interests of Named Experts and Counsel.

Not applicable.

Item 6. Indemnification of Directors and Officers.

Cayman Islands law does not limit the extent to which a company’s memorandum and articles of association may provide for indemnification of directors and officers, except to the extent any such provision may be held by the Cayman Islands courts to be contrary to public policy, such as to provide indemnification against civil fraud or the consequences of committing a crime. The Registrant’s amended and restated memorandum and articles of association provide for indemnification of directors and officers against any liability, action, proceeding, claim, demand, costs, damages or expenses, including legal expenses, which they may incur as a result of any act or failure to act in carrying out their functions other than such liability (if any) that they may incur by reason of their own actual fraud or willful default.

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In addition, the Registrant has entered into separate indemnification agreements with its directors and officers, pursuant to which the Registrant has agreed to indemnify its directors and officers against certain liabilities and expenses incurred by such persons in connection with claims by reason of their being such a director or officer.

The Registrant has purchased and intends to maintain insurance on behalf of each person who is or was a director or officer of the Registrant against any loss arising from any claim asserted against him or her and incurred by him or her in any such capacity, subject to certain exclusions.

Item 7. Exemption from Registration Claimed.

Not applicable.

Item 8. Exhibits.

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Item 9. Undertakings.

A. The undersigned Registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement.

Provided, however, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

B. The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the Registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

C. Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the

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event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Santa Clara, California, on the 29^th day of March, 2019.

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Feng-Ming Wang and Kevin C. Eichler, jointly and severally, as his true and lawful attorneys-in-fact and agents with full power of substitution, for him in any and all capacities, to sign the Registration Statement on Form S-8 of Ambarella, Inc., and any or all amendments (including post-effective amendments thereto), and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully for all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or his or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement on Form S-8 has been signed by the following persons in the capacities and on the dates indicated.

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Exhibit 5.1

Our ref  MUL/604688-000001/54440049v2

Ambarella, Inc.

PO Box 309, Ugland House

Grand Cayman

KY1-1104

Cayman Islands

29 March 2019

Dear Sirs

Ambarella, Inc.

We have acted as Cayman Islands counsel to Ambarella, Inc. (the “Company”) to provide this legal opinion in connection with the Company’s registration statement on Form S-8, including all amendments or supplements thereto (the “Form S-8”), filed with the United States Securities and Exchange Commission (the “Commission”) under the United States Securities Act of 1933 (the “Act”), as amended (the “Registration Statement”) relating to the reservation for issuance of: (i) 1,453,659 Ordinary Shares of the Company of a par value of US$0.00045 each (the “2012 Shares”), upon the granting of certain awards under the 2012 Equity Incentive Plan (the “2012 Plan”); (ii) 403,794 Ordinary Shares of the Company of a par value of US$0.00045 each (the “ESPP Shares” and, together with the 2012 Shares, the “Shares”), to be issued under the Amended and Restated 2012 Employee Stock Purchase Plan (the “ESPP” and together with the 2012 Plan, the “Plans”).

We have reviewed originals, copies, drafts or conformed copies of the following documents, and such other documents as we deem necessary:

The following opinions are given only as to, and based on, circumstances and matters of fact existing and known to us on the date of this opinion letter. These opinions only relate to the laws of the Cayman Islands which are in force on the date of this opinion letter. In giving the following opinions, we have relied (without further verification) upon the completeness and accuracy of the Director’s Certificate and the Certificate of Good Standing. We have also relied upon the following assumptions, which we have not independently verified:

Save as aforesaid we have not been instructed to undertake and have not undertaken any further enquiry or due diligence in relation to the transaction the subject of this opinion.

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Based upon, and subject to, the foregoing assumptions and the qualification set out below, and having regard to such legal considerations as we deem relevant, we are of the opinion that the Shares to be offered and issued by the Company pursuant to the provisions of the Plans, have been duly authorised for issue, and when issued by the Company pursuant to the provisions of the Plans for the consideration fixed thereto and duly registered in the Company’s register of members (shareholders), will be validly issued and (assuming that all of the Consideration is received by the Company) will be fully paid and non-assessable.

The opinions expressed above are subject to the following qualification:

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement. In providing our consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the Rules and Regulations of the Commission thereunder.

This opinion is addressed to you and may be relied upon by you and your counsel. This opinion is limited to the matters detailed herein and is not to be read as an opinion with respect to any other matter.

Yours faithfully

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Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of Ambarella, Inc. of our report dated March 29, 2019 relating to the financial statements and the effectiveness of internal control over financial reporting, which appears in Ambarella Inc.’s Annual Report on Form 10-K for the year ended January 31, 2019.

/s/ PricewaterhouseCoopers LLP

San Jose, California

March 29, 2019