This study determines the extent of American pilot participation as members of the Royal Air Force, flying in the Battle of Britain. It also examines the recruiting mechanism by which the Americans became involved in the war and documents their contributions as combat pilots during the battle itself. Research reveals that, while many American citizens were recruited to fly for Britain during the summer of 1940, only six Americans are known to have actually participated in the Battle of Britain, fought between 12 August and 15 September 1940. These men not only demonstrated America's determination to support her allies, but materially contributed to Britain's cause by destroying two and one half enemy aircraft, probably destroying five others, and damaging two more during their brief RAF careers.