The Coates Swalesong is a 1970s British two-seat homebuilt monoplane.
The Swalesong S.A.II was designed and built by J. R. Coates. It is a low-wing wooden construction (spruce with plywood skin) cantilever monoplane with a fixed tricycle undercarriage, with pilot and passenger sitting side-by-side in an enclosed cockpit with a sliding canopy. It first flew on 2 September 1973, powered by a Continental PC60 Ground Power Unit converted to Continental C90 standard. A simplified version, the Swalesong S.A.III, was designed for homebuilding, which could be powered by engines of .
Only one S.A.II G-AYDV and one simplified S.A.III were built. The Swalesong S.A.II survives at Breighton Airfield, East Yorkshire. The CAA G-INFO website shows that its registration is current in February 2021.