The Fokker D.IV was a German fighter biplane of World War I, a development of the D.I.
The Fokker D.IV had a more powerful Mercedes D.III engine, and the first Fokker front-line design to use ailerons in place of wing warping from the start for roll control.
The aircraft was purchased in small numbers by the German Army and saw service on the Western Front.
The Swedish Air Force also bought four examples of the type.