Glenn Emile Duncan (May 12, 1918 – July 4, 1998) was a career officer in the United States Air Force and one of the leading aces of Eighth Air Force in World War II in Europe and the top ace of the 353rd Fighter Group. Duncan was credited with 19.5 victories, one probable victory, and seven damaged German aircraft. He also destroyed at least nine enemy aircraft on the ground, while flying P-47 Thunderbolts with the 353rd Fighter Group. He flew combat missions in the P-47 Thunderbolts and P-51 Mustangs in Europe.