The third USS Proteus (AS-19) was a Fulton-class submarine tender in the United States Navy.
Proteus was laid down by the Moore Shipbuilding and Dry Dock Company, Oakland, California, 15 September 1941; launched 12 November 1942; sponsored by Mrs. Charles M. Cooke, Jr.; and commissioned 31 January 1944, Capt. Robert W. Berry in command.