United States securities and exchange commission logo December 7, 2023 Anirvan Ghosh, Ph.D. Chief Executive Officer Unity Biotechnology, Inc. 285 East Grand Avenue South San Francisco, CA 94080 Re: Unity Biotechnology, Inc. Registration Statement on Form S-3 Filed December 6, 2023 File No. 333-275924 Dear Anirvan Ghosh: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Joshua Gorsky at 202-551-7836 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Rick A. Werner, Esq.