USS R-7 (SS-84) was an R-class coastal and harbor defense submarine of the United States Navy. Her keel was laid down on 6 December 1917 by the Fore River Shipbuilding Company in Quincy, Massachusetts. She was launched on 5 April 1919 sponsored by Mrs. Ivan E. Bass, and commissioned on 12 June 1919 with Lieutenant Commander Eric F. Zemke in command.