Jeffrey Kindersley Quill, OBE, AFC, FRAeS (1 February 1913 – 20 February 1996) was a British test pilot who served on secondment with the Royal Air Force and Royal Naval Volunteer Reserve during the Second World War. He was also the second man to fly the Supermarine Spitfire after Vickers Aviation's chief test pilot, Joseph "Mutt" Summers. After succeeding Summers as Vickers' chief test pilot, Quill test-flew every mark of Spitfire. Quill's work on the aircraft aided its development from a promising but untried prototype to become, with the Hawker Hurricane, an instrument of the Royal Air Force's victory in the Battle of Britain. The Spitfire later played a leading role in gaining Allied air superiority over Europe. Quill later wrote two books about the Spitfire.