Exhibit 5.1

May 25, 2018

Coherus BioSciences, Inc.

333 Twin Dolphin Drive, Suite 600

Redwood City, CA 94065

Ladies and Gentlemen:

We have acted as special counsel to Coherus BioSciences, Inc., a Delaware corporation (the “Company”), in connection with the proposed issuance of up to 5,948,274 shares of common stock, par value $0.0001 per share (the “Shares”). The Shares are included in a registration statement on Form S-3 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on December 18, 2015 (Registration No. 333–208625) (as amended, the “Registration Statement”), a base prospectus dated January 21, 2016 (the “Base Prospectus”) and a prospectus supplement dated May 22, 2018 (the “Prospectus Supplement,” and together with the Base Prospectus, the “Prospectus”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act. 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.

May 25, 2018

Page 2

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when (i) the Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the purchasers, and (ii) have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the form of underwriting agreement most recently filed as an exhibit to the Registration Statement, (a) the issue and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and (b) the Shares will be validly issued, and (c) the Shares will be fully paid and nonassessable. In rendering the foregoing opinion, we have assumed that the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the General Corporation Law of the State of Delaware.

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 Company’s Form 8-K dated May 25, 2018 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.

Very truly yours,

/s/ Latham & Watkins LLP