Please wait

Exhibit 5.1

			801 Jefferson Avenue, Suite 300 Redwood City, California 94063 Tel: +1.650.328.4600 Fax: +1.650.463.2600 www.lw.com
			FIRM / AFFILIATE OFFICES
			Austin			Milan
			Beijing			Munich
			Boston			New York
			Brussels			Orange County
			Chicago			Paris
			Dubai			Riyadh
			Düsseldorf			San Diego
			Frankfurt			San Francisco
			Hamburg			Seoul
			Hong Kong			Silicon Valley
			Houston			Singapore
			London			Tel Aviv
			Los Angeles			Tokyo
			Madrid			Washington, D.C.

May 14, 2026

Cerebras Systems Inc.

1237 E. Arques Avenue

Sunnyvale, California 94085

Re: Registration Statement on Form S-8

To the addressee set forth above:

We have acted as counsel to Cerebras Systems Inc., a Delaware corporation (the “Company”), in connection with the registration for resale from time to time by certain selling stockholders (the “Selling Stockholders”) of up to 6,808,018 shares (the “Shares”) of the Company’s Class A common stock, $0.00001 par value per share, issued to the Selling Stockholders by the Company. The Shares are included in a registration statement (the “Registration Statement”) on Form S–8 under the Securities Act of 1933, as amended (the “Act”), and the related prospectus included in the Registration Statement (the “Prospectus”), filed with the Securities and Exchange Commission (the “Commission”) on May 14, 2026. 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 the Prospectus, other than as expressly stated herein with respect to the issue 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, and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, the Shares are validly issued, fully paid and non-assessable.

---

May 14, 2026

Page 2

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 and to the reference to our firm in the Prospectus under the heading “Legal Matters.” 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.

			Sincerely,
			/s/ Latham & Watkins LLP