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.

In 1902, Bill and Glenn both played pro football for the Syracuse Athletic Club during the first World Series of Football, held at Madison Square Garden.

It was during this event, that Warner played in the first professional indoor football game as his Syracuse squad upset the heavily favored "New York" team.

This biographical article relating to a college football coach first appointed in the 1900s is a stub.