William Jay Warner (January 24, 1881 – February 12, 1944) was an American football player and coach. Warner graduated from Cornell University in 1903 and was a member of the Sphinx Head Society. He was elected to the College Football Hall of Fame in 1971. Following his playing career at Cornell University, Warner was the head football coach at Cornell University, the University of North Carolina, Colgate University, St. Louis University, and the University of Oregon. He also coached football at Sherman Institute—now known as Sherman Indian High School—in Riverside, California.