The DH.29 Doncaster was ordered by the British Air Ministry as an experimental long-range monoplane. The aircraft was a high-wing cantilever monoplane with unswept wing of wooden structure with a fabric covering. It had a box section wooden fuselage with a single fin. The crew of two were in an open cockpit ahead of the wing. Two aircraft were built between 1920 and 1921 at Stag Lane Aerodrome. Early testing of the first aircraft (SerialJ6849) resulted in a redesign of the engine installation. The second aircraft (Registered G-EAYO) was built as a 10-seat commercial aircraft. The airlines were not interested in an untried monoplane and further development was abandoned and effort was put into the de Havilland DH.34 with a biplane configuration. A proposed military reconnaissance version, the DH.30, was never built.
The two aircraft finished their life at RAF Martlesham Heath on tests and trials particularly on the thick-section cantilever wings. The Doncaster was the first British aircraft to use thick-section cantilever wings.