Exhibit 5.1

	140 Scott Drive
	Menlo Park, California 94025
	Tel: +1.650.328.4600 Fax: +1.650.463.2600
	www.lw.com
	FIRM / AFFILIATE OFFICES
	Beijing	Moscow
	Boston	Munich
	Brussels	New York
	Century City	Orange County
	Chicago	Paris
September 21, 2021	Dubai	Riyadh
	Düsseldorf	San Diego
	Frankfurt	San Francisco
	Hamburg	Seoul
	Hong Kong	Shanghai
	Houston	Silicon Valley
	London	Singapore
	Los Angeles	Tokyo
	Madrid	Washington, D.C.
	Milan

Amplitude, Inc.

201 Third Street, Suite 200

San Francisco, California 94103

Re: Registration Statement on Form S-8

Ladies and Gentlemen:

We have acted as special counsel to Amplitude, Inc., a Delaware corporation (the “Company”), in connection with the registration by the Company of 51,675,511 shares of Class A Common Stock of the Company, par value $0.00001 per share (“Class A Common Stock”), and 29,615,899 shares of Class B Common Stock of the Company, par value $0.00001 per share (collectively, the “Shares”), issuable under the Company’s 2014 Stock Option and Grant Plan, as amended (the “2014 Plan”), 2021 Incentive Award Plan (the “2021 Plan”) and 2021 Employee Stock Purchase Plan (together with the 2014 Plan and the 2021 Plan, the “Plans”).

The Shares are included in a registration statement on Form S-8 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on September 21, 2021 (the “Registration Statement”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related prospectus, other than as expressly stated herein with respect to the issuance of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware (the “DGCL”), and we express no opinion with respect to any other laws.

September 21, 2021

Page 2

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when the Shares shall have been duly registered on the books of the transfer agent September 21, 2021 and registrar therefor in the name or on behalf of the purchasers, or certificates representing the Shares have been manually signed by an authorized officer of the transfer agent and registrar therefor, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the applicable Plans, assuming in each case that the individual issuances, grants or awards under the applicable Plans are duly authorized by all necessary corporate action and duly issued, granted or awarded and exercised in accordance with the requirements of law and the applicable Plans (and the agreements and awards duly adopted thereunder and in accordance therewith), the issue and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and non-assessable. In rendering the foregoing opinion, we have assumed that the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the DGCL.

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as an exhibit to the Registration Statement. In giving such 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.

Very truly yours,

/s/ Latham & Watkins LLP