USS R-2 (SS-79) was an R-class coastal and harbor defense submarine of the United States Navy. Her keel was laid down on 16 October 1917 by the Fore River Shipbuilding Company in Quincy, Massachusetts. She was launched on 23 September 1918 sponsored by Mrs. Charles M. Cooke, and commissioned at Boston, Massachusetts, on 24 January 1919 with Lieutenant Commander Charles Maynard "Savvy" Cooke, Jr., in command.