Lieutenant Frank Leaman Baylies (23 September 1895—17 June 1918) was an American World War I flying ace credited with twelve aerial victories while flying in the French Aeronautique Militaire. Having originally volunteered for the Ambulance Corps, Baylies transferred into French aviation in May 1917. After scoring his 12 victories with the French, he transferred into American aviation service but remained with the French until his death in action.