Cecil Frank Isbell was an American football player and coach. He played five years in the National Football League with the Green Bay Packers, leading them to the NFL Championship in 1939. He retired after the 1942 season to become an assistant coach at his alma mater, Purdue University, and the following year became its head coach for three seasons.

Isbell was the head coach of the Baltimore Colts of the All-America Football Conference from 1947 to 1949, resigning after four winless games. He then became an assistant under former head coach Curly Lambeau, now with the Chicago Cardinals. When Lambeau resigned late in the 1951 season, Isbell was the interim head coach for the final two games, which they split. Isbell’s pro head coaching record was 10-23-1. He was hired as an assistant coach with the Dallas Texans if the NFL in 1952.

Isbell was inducted into the College Football Hall of Fame as a player in 1967.