Williams was signed by the Green Bay Packers on November 29, 2006. In 2007, Tramon earned a roster spot with a solid preseason and went on to play in every contest, as well as both playoff games, with one start, rotating as a nickel and dime back, while posting 11 tackles, 1 interception, and 4 passes defensed. He also had a team-leading 30 kickoff returns for a 22.8 average, with 6 punt returns for a 19.7 average, a touchdown, with 7 special teams tackles. In 2008, he played in every contest for the second straight season, including 9 starts. He was third in the NFC with five interceptions and 52 tackles (45 solo). He was third on the team with 14 passes defensed, 5 special teams tackles, and 2 forced fumbles. In 2009, he played in every contest as well (third straight season), including a career-high 10 starts while Al Harris was injured. He had 4 interceptions, and a career high 55 tackles, with 15 passes defensed and 1 sack.