Cymabay Therapeutics (CBAY) 10-K 2021 FY Annual report

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the following Registration Statements:

(1) Registration Statement (Form S-3 No. 333-239670) of CymaBay Therapeutics, Inc., and

(2) Registration Statements (Form S-8 Nos. 333-195211, 333-198289, 333-202941, 333-210453, 333-216905, 333-223687, 333-226741, 333-229953, and 333-254697) pertaining to the Metabolex, Inc. 2003 Equity Incentive Plan, the CymaBay Therapeutics, Inc. 2013 Equity Incentive Plan, and the CymaBay Therapeutics, Inc.2020 New Hire Plan;

of our report dated March 17, 2022, with respect to the consolidated financial statements of CymaBay Therapeutics, Inc. included in this Annual Report (Form 10-K) of CymaBay Therapeutics, Inc. for the year ended December 31, 2021.

/s/ Ernst & Young LLP

Redwood City, California

March 17, 2022