The Martin MO was an American observation monoplane built by the Glenn L. Martin Company of Cleveland Ohio for the United States Navy. In the early 1920s the United States Navy became interested in a thick aerofoil section cantilever wing United States military observation aircraft developed by the Dutch company Fokker. The Navy's Bureau of Aeronautics designed a three-seat observation monoplane to use a similar wing.
Made by Glenn L. Martin Company.