Williams initially entered his name in the 2005 NBA draft and participated in pre-draft workouts, but withdrew in April without having hired an agent, something that allowed him to come back to Wake Forest for his senior year. In his last season of college basketball Williams was again in the starting five (34 out of 34 games), averaging 32.6 minutes. He made his debut in the first game of the season on November 10, 2005 against Mississippi Valley State and posted 22 points and 9 rebounds. On January 11, 2006 he recorded 22 points and 20 rebounds (career high) against Clemson. His season averages were all career-highs: 16.3 points, 8.9 rebounds, 1 assists, 1.3 steals and 1.1 blocks; he also led the ACC in field goal percentage with .619, and was third in the conference for rebounding average. At the end of the year he was named in the All-ACC third team.