USS R-8 (SS-85) was an R-class coastal and harbor defense submarine of the United States Navy. Her keel was laid down on 4 March 1918 by the Fore River Shipbuilding Company, Quincy, Massachusetts. She was launched on 17 April 1919 sponsored by Ms. Penelope Potter, and commissioned on 21 July 1919 with Lieutenant Commander Philip C. Ransom in command.