USS El Capitan (ID-1407) was a United States Navy cargo ship in commission from 1918 to 1919. El Capitan was built as the commercial cargo ship SS California in 1917 by the Newport News Shipbuilding and Drydock Company at Newport News, Virginia. She soon was renamed SS Oliver J. Olsen and then SS El Capitan. After the United States entered World War I, the United States Shipping Board took control of El Capitan, and transferred her to the U.S. Navy for war service on 21 March 1918. The Navy assigned her the naval registry Identification Number (Id. No.) 1407 and commissioned her the same day as USS El Capitan with Lieutenant Commander J. H. Halsey, USNRF, in command.
Assigned to the Naval Overseas Transportation Service, El Capitan made four transatlantic voyages between 29 March 1918 and 23 November 1918. She carried various supplies and equipment from United States East Coast ports to Brest, Le Verdon-sur-Mer, and Le Havre in France, and to Plymouth and Devonport in England. On her second voyage, one day out of Philadelphia, Pennsylvania, she sighted a German submarine abeam. Her guns forced the submarine to dive before it could attack.
El Capitan was decommissioned on 1 February 1919 and transferred to the Shipping Board the same day for return to her owner, the Southern Pacific Steamship Company. The ship returned to commercial service as SS El Capitan.
During World War II, El Capitan was owned by the United States War Shipping Administration and, beginning in June 1941, was operated by United States Lines. She was transferred to Panamanian registry (a flag of convenience) at the beginning of October 1941. El Capitan was disabled by German aircraft on 9 July 1942 while part of Arctic convoy PQ-17, and sank the following day.