Kenneth "Jack" Mollenkopf (November 24, 1905 – December 4, 1975) was the head football coach at Purdue University from 1956 until 1969. Mollenkopf was also an assistant coach at Purdue from 1947 to 1955 under Stu Holcomb.Mollenkopf was a successful football coach competing at high school and college levels and is widely acknowledged as the greatest football coach in Purdue's history. While coaching high school, he led Toledo Waite to three national championships.