The Siemens-Schuckert D.III was a German single-seat fighter built by Siemens-Schuckert Werke. The D.III was a development of the earlier Siemens-Schuckert D.IIc prototype. The D.III was an equal-span sesquiplane powered by a 160 hp (119 kW) Siemens-Halske Sh.III bi-rotary engine.
Approximately 41 D.IIIs were delivered to frontline units between April and May 1918. Most aircraft were supplied to Jagdgeschwader II, whose pilots were enthusiastic about the new aircraft's handling and rate of climb. In late May 1918, Jagdgeschwader II replaced its D.IIIs with the older Fokker Dr.I. The remaining D.III aircraft were returned to the Siemens-Schuckert factory, where they were retrofitted with new Sh.IIIa engines, an enlarged rudder, and cutaway cowlings that provided improved airflow. A further 30 new production D.IIIs incorporated these modifications. Total production amounted to 80 aircraft.