A versatile infielder, Dennis played for the Southwest Missouri State University baseball team from 1968 to 1970. He was co-captain of his Southwest Missouri team in 1970, and was co-recipient of the Most Valuable Player award that same year. Dennis also won the Topps Collegiate Second Team All-American Award.

In 1994, he was inducted into the Southwest Missouri State University Athletic Hall of Fame. In later years, Dennis was a baseball coach for the Ballwin Athletic Association.