USS O-15 (SS-76) was an O-class submarine of the United States Navy. Her keel was laid down on 21 September 1916 by California Shipbuilding Company in Long Beach, California. The later O-boats (O-11 through O-16) were designed by Lake Torpedo Boat to different specifications from the earlier ones designed by Electric Boat. They performed much less well, and are sometimes considered a separate class. O-15 was launched on 12 February 1918, sponsored by Mrs. J. J. Murphy, and commissioned on 27 August 1918 with Lieutenant C. K. Martin in command.