The Dewoitine D.21 was a 1920s French open-cockpit, fixed-undercarriage, parasol winged monoplane fighter aircraft.
The prototype D.21 was a development of the D.12. The aircraft was license-built in Switzerland (by EKW), Czechoslovakia (by Skoda and known as the Skoda-Dewoitine D.1) and Argentina (by FMA). One Turkish D.21 was fitted with a modified wing and named Orhanelli.
Argentina bought seven French-built D.21s, and built another 38 under license by FMA from 1929 to 1932. The type remained in service until 1941. Turkey bought a number, and Czechoslovakia built 25 for their air force.