He played college football for the UCF Knights and was selected by the Green Bay Packers in the fourth round of the 2008 NFL draft.

He earned second-team all-state and first-team all-area honors as an offensive lineman as a senior.

Propelled in part by Sitton's standout year, the Knights won their first-ever conference title in 2007.

[5] In 2010, he was named Offensive Lineman of the Year by the NFL Alumni Association and was selected as a Pro Bowl alternate.

[11] On January 3, 2016, Sitton started his first career game at left tackle in place of the injured David Bakhtiari as the Packers played the Minnesota Vikings in the regular season finale that decided the NFC North champion.

[12] Sitton revealed that his reasons for signing with the Bears included: how quickly the deal got done, the weather in the midwest compared to "too damn hot" in the south and close proximity to where he had lived in the Green Bay area.

[13] Sitton was forced to miss the team's first meeting against the Packers, a game at Green Bay on October 20.

Sitton had suffered an ankle injury on one of the final plays of Chicago's prior game against Jacksonville.

[15] The Bears narrowly lost to Green Bay in one of the coldest games ever played at Soldier Field.

Despite missing three games due to an ankle injury, and the Bears' worst record in a 16-game season in franchise history, Sitton was named to the Pro Bowl replacing former teammate T. J. Lang.

"[16] In March 2017, Sitton revealed that he felt like he was hitting a milestone achievement entering his 10th NFL season.

On February 20, 2018, the Bears declined an option on Sitton's contract, making him a free agent.

[19][20] On September 14, 2018, Sitton was placed on season-ending injured reserve after suffering a torn rotator cuff.

Sitton recently donated to his alma mater, Pensacola Catholic High School, as part of a campaign to add onto the athletic facilities and a new cafeteria.