He was one of nine children born to Lucious and Jessie Selmon, and was raised on a farm near Eufaula, Oklahoma.
Selmon played nose guard for the Oklahoma Sooners for coaches Chuck Fairbanks and Barry Switzer.
Selmon's younger brothers, Dewey and Lee Roy, joined him at the University of Oklahoma and in one period, all three played as defensive linemen.
Lee Roy won the Outland Trophy and Lombardi Award, and in 1995 he was the Sooners' first inductee in the Pro Football Hall of Fame.
Selmon helped develop four players who later earned All-America honors: nose guard Reggie Kinlaw, Rick Bryan, Kevin Murphy and defensive end Darrell Reed.
He participated in the NFL's Minority Coaching Fellowship Program from 1980 to 1989, and worked with the Denver Broncos' linebackers and defensive ends.
Two Jaguars, outside linebacker Kevin Hardy and defensive end Tony Brackens, earned 'All-Pro' honors.