Kenneth Webster "Jack" Mollenkopf (November 24, 1903 – 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 died of cancer on December 4, 1975, at the Mayo Clinic in Rochester, Minnesota .