The Franklin O-200 (company designation 4AC-199) was an American air-cooled aircraft engine of the early 1940s. The engine was of four-cylinder, horizontally-opposed layout and displaced 200abbr=onNaNabbr=on. The power output ranged between 65abbr=onNaNabbr=on and 100abbr=onNaNabbr=on depending on variant. The O-200-5 (4ACG-199) featured a geared propeller drive.