Exhibit 24

United Airlines Holdings, Inc.

Authorization and Designation to Sign and File Section 16 Reporting Forms and
Form 144s

     The undersigned does hereby authorize and designate E. Anna Ha or Sarah
Hagy (the "Authorized Persons") to prepare, sign and file on his behalf: (i) any
and all Forms 3, 4, 5 and Form ID, including any amendments thereto, relating to
equity securities of United Airlines Holdings, Inc., a Delaware corporation (the
"Company") with the Securities and Exchange Commission (the "SEC")  pursuant to
the requirements of Section 16 of the Securities Exchange Act of 1934, as
amended ("Section 16"), and the rules promulgated thereunder; and (ii) any and
all Forms 144 relating to equity securities of the Company with the SEC pursuant
to Rule 144 under the Securities Act of 1933, as amended, in each case which may
be necessary or desirable as a result of his ownership of or transaction in
securities of the Company.  The undersigned further hereby authorizes and
designates the Authorized Persons to do and perform any and all acts for and on
his behalf as may be necessary or desirable to prepare, sign and file the forms
contemplated by this Authorization.  The undersigned hereby confirms any action
relating to the preparation, signing and filing of (i) and (ii) above, performed
by the above mentioned individuals on his behalf and revokes any prior
Authorization and Designation to Sign and File Section 16 Reporting Forms and
Forms 144 relating to equity securities of the Company.  This authorization,
unless earlier revoked in writing, shall be valid until the undersigned's
reporting obligations under Section 16 and Rule 144 with respect to securities
of the Company shall cease.

IN WITNESS WHEREOF, the undersigned has executed this Authorization and
Designation this 10th day of March 2022.

                                 Signature:     /s/ Michael J. Hamilton
                                                -------------------------------

                                 Printed Name:  Michael J. Hamilton
                                                -------------------------------