July 26, 2024 Daniel Lochner Chief Financial Officer Tectonic Therapeutic, Inc. 490 Arsenal Way Suite 210 Watertown, MA 02472 Re: Tectonic Therapeutic, Inc. Registration Statement on Form S-1 Filed July 19, 2024 File No. 333-280909 Dear Daniel Lochner: 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 Tyler Howes at 202-551-3370 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Courtney T. Thorne, Esq.