Ken Donahue (1925 – March 21, 2001) was an American football player and coach. He played college football at the University of Tennessee and served as an assistant coach at the University of Alabama under Bear Bryant. Donahue and four other men, Pat Dye, Bill Oliver, and Paul Bryant, created the multiple defense scheme that allowed the players to switch defenses quickly. The 4-3 and 5-2 schemes are still used by NCAA and NFL teams today. The scheme became popular because it allowed players to learn a minimum amount of technique, while allowing them to maximize the use of their strengths. Donahue died on March 21, 2001 at the age of 76.