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.
Statement on Form S-3
                                                            Filed December 6,
                                                            File No. 333-275924

       Dear Anirvan Ghosh:

              This is to advise you that we have not reviewed and will not
review your registration

               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.


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Rick A. Werner, Esq.