POWER OF ATTORNEY

Know all by these presents that, the undersigned hereby constitutes and
appoints each of Faye C. Brown, Jon Filderman, Kelly Grez and Courtney
Ausfahl, signing singly, the undersigned's true and lawful
attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer of Merck & Co., Inc. (the "Company"), Forms 3, 4
and 5 in accordance with Section 16(a) of the Securities Exchange Act of
1934 and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such
Forms 3, 4 or 5, complete and execute any amendment or amendments
thereto, and timely file such form with the United States Securities and
Exchange Commission and any stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf
of the undersigned pursuant to this Power of Attorney shall be in such form
and shall contain such terms and conditions as such attorney-in-fact may
approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and
powers herein granted, as fully to all intents and purposes as the undersigned
might or could do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or
such attorney-in-fact's substitute or substitutes, shall lawfully do or cause
to be done by virtue of this Power of Attorney and the rights and powers
herein granted.  The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect
to the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 4th day of August 2020.

					/s/ David Williams