SS Mission Buenaventura was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II.

The lead ship in her class of fleet oilers, she was named for Mission San Buenaventura located in Ventura, California.

SS Mission Buenaventura was laid down 29 March 1944 under a Maritime Commission contract by Marinship Corporation, Sausalito, California; launched 28 May 1944; sponsored by Mrs. Fred W. Boole; and delivered 28 June 1944.

Chartered to Deconhill Shipping Company, for operations, she spent the remainder of the War supporting the victorious Allied forces in the Pacific.

Reacquired by the Navy on 10 November 1961 she was transferred to MSTS control on the same date and chartered to Mathiasen's Tanker Industries, Inc. for operations, where she served as part of the Ready Reserve Force fleet.