Prior to the 2005 season, Williams signed with the Minnesota Vikings, the 1st signing for the team in 2005 free agency and a priority signing. Following an advice by then defensive coordinator Mike Tomlin, Williams lost 15 pounds in the offseason. Williams played nose tackle in the Minnesota Vikings 4-3 defense, with teammate Kevin Williams playing the Under Tackle position. They were known collectively as the "Williams Wall" as well as the "Williams Wrecking Crew" due to their physical presence at the line of scrimmage, an attribute that helped them lead the Vikings to the best rushing defense in the league for three consecutive seasons (2006-2008). As a player for the Vikings, he was selected to his first Pro Bowl in 2006, and followed with consecutive selections in 2007 and 2008. He was also a second-team All-Pro selection in 2007.