Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2013 Equity Incentive Plan and 2020 New Hire Plan of CymaBay Therapeutics, Inc. of our report dated March 25, 2021, with respect to the consolidated financial statements of CymaBay Therapeutics, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2020, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Redwood City, California

March 25, 2021