Amos Alonzo Stagg (August 16, 1862 – March 17, 1965) was an American athlete and pioneering college coach in multiple sports, primarily football. He served as the head football coach at Springfield College (1890–1891), the University of Chicago (1892–1932), and the College of the Pacific (1933–1946), compiling a career college football record of 314–199–35. His Chicago Maroons teams of 1905 and 1913 have been recognized as national champions. He was also the head basketball coach for one season at the University of Chicago (1920–1921), and the head baseball coach there for 19 seasons (1893–1905, 1907–1913).
Stagg played football as an end at Yale University and was selected to the first College Football All-America Team in 1889. He was inducted into the College Football Hall of Fame as both a player and a coach in the charter class of 1951 and was the only individual honored in both roles until the 1990s. Influential in other sports, Stagg developed basketball as a five-player sport and was elected to the Basketball Hall of Fame in its first group of inductees in 1959.
Stagg was born in West Orange, New Jersey and attended Phillips Exeter Academy. Playing at Yale University, where he was a divinity student, and a member of the Psi Upsilon fraternity and the secret Skull and Bones society, he was an end on the first All-America team, selected in 1889.