Unity Biotechnology, Inc.

3280 Bayshore Blvd

Brisbane, California 94005

April 30, 2018


United States Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549-6010




Suzanne Hayes, Assistant Director

James Rosenberg, Senior Assistant Chief Accountant

Jeffrey Gabor, Staff Attorney

Ada Sarmento, Staff Attorney

Lisa Vanjoske, Assistant Chief Accountant

Vanessa Robertson, Senior Staff Accountant


   Unity Biotechnology, Inc. Registration Statement on Form S-1 (Registration No. 333-224163)

Ladies and Gentlemen:

In accordance with Rule 461 of Regulation C of the General Rules and Regulations under the Securities Act of 1933, as amended, we hereby request acceleration of the effective date of the Registration Statement on Form S-1 (File No. 333-224163) (the “Registration Statement”) of Unity Biotechnology, Inc. (the “Company”). We respectfully request that the Registration Statement become effective as of 4:00 p.m., Washington, D.C. time, on May 2, 2018, or as soon as practicable thereafter. Once the Registration Statement has been declared effective, please orally confirm that event with our counsel, Latham & Watkins LLP, by calling Brian Cuneo at (650) 463-3014.

Thank you for your assistance in this matter.


Very truly yours,
Unity Biotechnology, Inc.
By:   /s/ Keith R. Leonard
  Keith R. Leonard Jr.
  Chief Executive Officer


CC: Tamara L. Tompkins, Unity Biotechnology, Inc.
     Alan C. Mendelson, Latham & Watkins LLP
     Mark V. Roeder, Latham & Watkins LLP
     Brian J. Cuneo, Latham & Watkins LLP
     Alan F. Denenberg, Davis Polk & Wardwell LLP