POWER OF ATTORNEY

    The undersigned hereby authorizes and designates each of Kim O. Warnica and John D.
Montanti (the "Attorneys") as her fully authorized attorney for the purpose of signing and filing on
behalf of the undersigned all forms which are permitted or required to be filed pursuant to Section
16(a) of the Securities Exchange Act of 1934 (the "Forms") concerning the undersigned's interest
in securities of Marathon Oil Corporation ("MOC") and/or the undersigned's status with respect to
MOC.  The Forms shall include, but are not limited to, Form IDs and any other documents
necessary or appropriate to obtain codes and passwords enabling the undersigned to make
electronic filings with the SEC, and Forms 3, 4 and 5.
       This Power of Attorney authorizes each of the Attorneys to sign and file the Forms on
behalf of the undersigned from the date hereof 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 MOC, unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing Attorneys.  This Power of Attorney is automatically revoked with respect to each
Attorney individually upon cessation of such Attorney's employment with MOC.

Dated:  December 8, 2021

                        /s/ Marcela E. Donadio
                        Marcela E. Donadio