United States securities and exchange commission logo March 18, 2022 Alexander Nguyen, Esq. General Counsel Unity Biotechnology, Inc. 285 East Grand Avenue South San Francisco, CA 94080 Re: Unity Biotechnology, Inc. Registration Statement on Form S-3 Filed March 15, 2022 File No. 333-263574 Dear Mr. Nguyen: 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 Tim Buchmiller at (202) 551-3635 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Brian J. Cuneo, Esq.