Donnelly began his coaching career at his alma mater, Father Ryan High School in Nashville, Tennessee. He served as the head football coach there from 1974 to 1975, tallying a mark of 21–2. His 1974 team went 13–0 and won the Tennessee Class AAA title. In 1976 Donnelly joined the football staff at Vanderbilt University, coaching the offensive backfield under head coach, Fred Pancoast.[3] Donnelly went on to be the head coach at Austin Peay for two seasons, and at MTSU for twenty seasons.
Later life
After the conclusion of his coaching career, Donnelly served as athletic director at MTSU for several years. In 2006, he became CEO of Backfield in Motion, an organization dedicated to fostering academic and athletic abilities among inner city youth.[2] In October 2015, a statue of Donnelly was unveiled on the MTSU campus.[4]