A two-time All-Pro and a five-time Pro Bowler, Mathis won the Super Bowl XLI with the Colts in 2006 over the Chicago Bears.

[4] In the summer of 2010, Mathis graduated with a degree in exercise science with a minor in physical education, and is a member of the Omega Psi Phi fraternity, Nu Epsilon chapter.

[7] During his second season, Mathis took another step forward as he increased his numbers to 36 tackles, 10.5 sacks and 6 forced fumbles, despite appearing only as a specialist and starting only 1 game.

[7] Following the 2005 season, Robert Mathis signed a 5-year extension with the Colts worth $30 million, making him one of the highest paid defensive ends in the league at the time.

[8] The following season, Mathis started every game for the first time in his career, recording a career-high 65 tackles along with 9.5 sacks and 6 forced fumbles.

[7] That year, Mathis helped the Colts go on to beat the Chicago Bears in Super Bowl XLI to become NFL Champions.

In November 2009, Mathis won his first career AFC Defensive Player of the Month award, and finished the season with 37 tackles, 9.5 sacks, and 5 forced fumbles.

On January 2, 2012, Mathis was added to the AFC Pro Bowl Roster to replace Patriots DE Andre Carter.

[14] Mathis began playing strong-side outside linebacker under new Colts head coach Chuck Pagano during the 2012 season.

[28] Mathis appeared as himself in the episode "Fluoride" of the comedy television series Parks and Recreation, alongside teammates Andrew Luck, Reggie Wayne, Adam Vinatieri, Anthony Castonzo, and Colts owner Jim Irsay.

Mathis a member of Straitway Truth Ministry, a Black Hebrew Israelite group that preaches Biblical literalism.