May 7, 2019

Lee Kalowski
Chief Financial Officer
Bicycle Therapeutics Ltd.
4 Hartwell Place
Lexington, Massachusetts 02421

       Re: Bicycle Therapeutics Ltd.
           Registration Statement on Form S-1
           Filed April 26, 2019
           CIK 0001761612

Dear Mr. Kalowski:

       We have reviewed your registration statement and have the following
comments. In
some of our comments, we may ask you to provide us with information so we may
understand your disclosure.

       Please respond to this letter by amending your registration statement
and providing the
requested information. If you do not believe our comments apply to your facts
circumstances or do not believe an amendment is appropriate, please tell us why
in your

       After reviewing any amendment to your registration statement and the
information you
provide in response to these comments, we may have additional comments.

Registration Statement on Form S-1 filed on April 26, 2019

Description of American Depositary Shares, page 212

1.     We note the revised disclosure regarding the waiver of jury trial
provision in page 223 of
       your registration statement. Please further revise your disclosure to
address any questions
       as to enforceability of such waiver and to state that, by agreeing to
the terms of the deposit
       agreement, investors will not be deemed to have waived our or the
       compliance with U.S. federal securities laws and the rules and
regulations promulgated
        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.
 Lee Kalowski
Bicycle Therapeutics Ltd.
May 7, 2019
Page 2

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration

       You may contact Jim Dunn at 202-551-3724 or Isaac Esquivel at
202-551-3395 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Liz Walsh at 202-551-3696 or Christopher Edwards at 202-551-6761 with
any other

FirstName LastNameLee Kalowski
                                                           Division of
Corporation Finance
Comapany NameBicycle Therapeutics Ltd.
                                                           Office of Healthcare
& Insurance
May 7, 2019 Page 2
cc:       Jonathan Schur
FirstName LastName