At Duke University, Williams, a 6-foot-2-inch, 195-pound point guard, became one of the few freshmen in school history to average double figures in scoring and was named ACC Rookie of the Year and National Freshman of the Year by The Sporting News, averaging 14.5 points, 6.5 assists and 4.2 rebounds per contest. The next season Williams started all 39 games and led the Devils to the 2001 NCAA National Championship, earning NABC Player of the Year honors.

Williams was selected by the Bulls with the second overall pick in the 2002 NBA Draft and was a starter in the Bulls' line-up for most of the 2002-2003 NBA season. On the night of June 19, 2003, Williams was riding a motorcycle at a fast speed on the North Side of Chicago. He crashed his motorcycle into a streetlight and was not wearing a helmet, nor was he licensed to ride a motorcycle in Illinois and was also violating the terms of his NBA Bulls contract by riding a motorcycle. Williams' injuries included a fractured pelvis, a severed main nerve in his leg, and three torn ligaments in his left knee, including the ACL. He required lengthy physical therapy to regain the use of his leg. Williams now works for as an NBA analyst.