He played nine seasons for three teams (Pittsburgh Steelers 1987-1991, Dallas Cowboys 1992-1993, Tampa Bay Buccaneers 1994-1995). He attended Baylor University where he won the Jim Thorpe Award as the top defensive back in college football. As a member of the Cowboys in 1993 he made the Pro Bowl.
In 2006, he was elected to the College Football Hall of Fame.
In Thomas' first season with the Cowboys he wore number 31 because reserve running back Curvin Richards wore number 27, the number Thomas wore for 5 seasons with the Steelers. When Richards was cut after the final regular season game in 1992 for fumbling, Thomas changed his number to 27 for the playoffs. The Cowboys went on to win the Super Bowl with Thomas recording 2 interceptions in a 52-17 victory over the Buffalo Bills.
He is also the older brother of former NFL football player, Eric Everett (of Texas Tech University), who played for the Philadelphia Eagles (1988-89), Tampa Bay Buccaneers (1990), Kansas City Chiefs (1991), and Minnesota Vikings (1992).
He currently runs an athletic camp called Thomas Everett Athletics.
Thomas was the first, and so far only, person to have his number retired at Daingerfield High School in early 1993 after the Dallas Cowboys won Super Bowl XXVII. His number hangs today in the Daingerfield High School field house.