The MacDonald S-20 was a single-seat sport aircraft designed in the United States in the early 1970s and marketed for home building. It was a conventional low-wing cantilever monoplane with fixed tailwheel undercarriage and an open cockpit. Construction was of metal throughout with a forward fuselage of welded steel tube construction with the rear fuselage built up of aluminium bulkheads and longerons.
Made by Homebuilt aircraft.