EXHIBIT 24
POWER OF ATTORNEY

     The undersigned hereby constitutes and appoints each of Richard Galanti,
John Sullivan, Alejandro Torres, and Gail E. Tsuboi, signing singly, as 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 Costco Wholesale Corporation (the "Company"), Forms 3,
4 and 5 in accordance with Section 16(a) of the Securities Exchange Act of 1934
and the rules thereunder (the "Exchange Act") and Form ID to obtain EDGAR codes
and related documentation for use in filing Forms 3, 4 and 5;

     (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 Form 3, 4
or 5, Form ID or Passphrase Update, complete and execute any amendment or
amendments thereto, and timely file such forms with the United States Securities
and Exchange Commission and any stock exchange or similar authority;

     (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; and

     (4)	seek or obtain, as the undersigned's attorney-in-fact and on the
undersigned's behalf, information regarding transactions in the Company's
securities from any third party, including brokers, and the undersigned hereby
authorizes any such person to release any such information to such
attorney-in-fact and approves and ratifies any such release of information.

     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 connection with 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 Exchange Act.

     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.

     This Power of Attorney does not relieve the undersigned from responsibility
for compliance with the undersigned's obligations under the Exchange Act,
including, without limitation, the reporting requirements under Section 16 of
the Exchange Act.  Additionally, although pursuant to this Power of Attorney the
Company will use commercially reasonable best efforts to timely and accurately
file Section 16 reports on behalf of the undersigned, the Company does not
represent or warrant that it will be able to in all cases timely and accurately
file Section 16 reports on behalf of the undersigned due to various factors,
including, but not limited to, the shorter deadlines mandated by the
Sarbanes-Oxley Act of 2002, possible time zone differences between the Company
and the undersigned and the Company's need to rely on others for information,
including the undersigned and brokers of the undersigned.

     IN WITNESS WHEREOF, the undersigned had caused this Power of Attorney to be
executed as of this 18th day of September, 2023.

By: /s/ John C. Sullivan
Name: John C. Sullivan