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.
Statement on Form S-3
                                                            Filed March 15,
                                                            File No. 333-263574

       Dear Mr. Nguyen:

              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 Tim
Buchmiller at (202) 551-3635 with any questions.


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Brian J. Cuneo, Esq.