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

Chartered to Pacific Tankers Inc., she spent the rest of the War supporting allied forces overseas (during which time she was awarded the National Defense Service Medal), until returned to the Maritime Commission on 20 April 1946 and laid up at the Maritime Commission Reserve Fleet at Mobile, Alabama.

Acquired by the Navy on 17 November 1947, she was designated as Mission Capistrano (AO‑112) and transferred to the Naval Transportation Service for duty.

She continued her voyages along the world's tanker routes transporting oil to and from the United States until early 1960, when she entered the Todd Pacific Shipyards at New Orleans, Louisiana for conversion to a "Sound Testing Ship."

Reclassified USNS Mission Capistrano (AG‑162) on 1 July 1960 she was modified to carry an ultra‑high‑powered sonar transducer array some five stories high and several tons in weight.