Sitton was drafted by the Green Bay Packers in the 4th round of the 2008 NFL Draft. In 2010, he was named Offensive Lineman of the Year by the NFL Alumni Association and was selected as a Pro Bowl alternate. Sitton was a key part of the Packers offensive line. Sitton started every game at right guard during the 2009 and 2010 seasons, including all the team's playoff games.