The Martin MS-1 was an experimental scout biplane ordered by the United States Navy and was intended to operate from a submarine.

Following World War I, the U.S. Navy Bureau of Aeronautics conducted studies concerning the possibility of submarine-borne observation and scouting aircraft.

The Navy ordered two types of aircraft, the Martin MS-1, constructed of wood and fabric, and the all-metal Cox-Klemin XS.

The MS-1 and the Cox-Klemin XS were used for the trials, mounted in a cylindrical pod behind the conning tower.

The first full cycle of surfacing, assembly, launching, retrieving, disassembly, and submergence took place on 28 July 1926, on the Thames River at New London, Connecticut using the XS-2.