He played college football for the Southern Jaguars and was selected in the third round of the 1991 NFL draft by the Phoenix Cardinals, where he spent 10 seasons.

[1][2] He attended the now defunct Alcee Fortier High School, where he played football on a team with three future NFL players: Maurice Hurst, Kevin Lewis, and Ashley Ambrose.

Eventually, after being encouraged by his old high school teammate Maurice Hurst, he decided to join the team as a walk-on.

Williams kept his involvement with the football team a secret from his family until he made the travel squad for the 2nd game of the season.

He made the ALL SAC team again and tied the Division I-AA, (now known as the NCAA Football Championship Subdivision) record for most interceptions with eleven.

By 1997, Williams had already notched four Pro Bowl appearances and had established himself as the Cardinals' top cornerback, routinely covering the opponents' lead receivers.

In 2000, he tied an NFL record, held by Jack Tatum of the Oakland Raiders, by returning a fumble (caused by Mark Maddox) 104 yards for a touchdown in a game against the Washington Redskins.

In Week 3 of the 1999 season, in a game played at Sun Devil Stadium and nationally televised on Monday Night Football, Williams delivered the hit which ultimately ended Hall of Fame San Francisco 49ers' quarterback Steve Young's career.

Young suffered a severe concussion that effectively ended his career; he didn't play again for the rest of the season, after which the 49ers all but forced him to retire.

[12] Williams was a finalist for the Pro Football Hall of Fame classes of 2012 and 2013 but did not get voted in on the final ballots both times.