Thomas R. Williams entered USC in the 2003 recruiting class that included Reggie Bush and LenDale White. Williams started 14 games at 3 different positions while playing college football at USC. He was all-Pac-10 honorable mention in 2007 and was invited to the East West Shrine Game and the Hula Bowl. Williams career stats include, 74 tackles, 1 sack, 3 fumbles forced, 5 passes defensed, 5 tackles for loss, 3 interceptions, and 37 interception return yards. In 2007 Williams had 56 tackles. He had 6 tackles in the 2008 Rose Bowl. During his time with the Trojans, Williams received guidance and feedback from veteran linebackers such as Lofa Tatupu, Matt Grootegoed, Dallas Sartz, Collin Ashton, and Oscar Lua. In order to see more playing time against the more experienced linebackers ahead of him, Williams focused and excelled at special teams play, particularly kickoff coverage. During his redshirtfreshman year he was an active member of the 2004 National Championship team, where he played behind Sartz at the strong-side spot. Early in the 2004 season, Williams was nicknamed "The Hitman" by coach Pete Carroll for his performance on special teams; the name stuck with him for his career at USC. During the 2005 season, Williams again backed up Sartz, but moved into the starting lineup for six games after Sartz suffered a shoulder injury; he also started twice in the middle and learned the weak-side responsibilities as well. During the 2006 season, when the Trojans fullbacks were decimated by injury, members of the offense such as Ryan Kalil, Sam Baker, and John David Booty, asked him to switch positions to fullback, a position he had played in high school. Thus Williams started twice at fullback and played several games that season on both offense and defense. Over the years, Williams played all three linebacker positions. Williams teammates voted him the team's most inspirational player in the 2007 season; he finished the regular season as the third-leading tackler among linebackers with 3½ tackles for losses, an interception and two forced fumbles on a defense that ranked second nationally. Thomas R. Williams graduated from USC in May 2008 with a degree in sociology.
Williams was selected 155th overall by the Jacksonville Jaguars in the 2008 NFL draft; he was the first person from his high school to be drafted in the NFL since Vince Newsome was drafted 97th overall in the 1983. Williams signed a four-year contract with the Jaguars. He played in six games for the Jaguars in 2008, recording one tackle. He was waived on September 5, 2009.
Williams was signed to the New England Patriots practice squad on November 10, 2009. He was promoted to the Patriots' active roster on January 6, 2010, in advance of their playoff game against the Baltimore Ravens, for which he was inactive. He was waived during final cuts on September 4, 2010.
Buffalo Bills
Williams was signed to the Buffalo Bills practice squad on October 12, 2010 and later added to the active roster. He played in two games for the Bills before being waived on December 11, 2010.
Carolina Panthers
Williams was signed to the Carolina Panthers practice squad on December 15, 2010, and was released on March 13, 2012.
