He played college football for the Rutgers Scarlet Knights and was selected by the Tennessee Titans with the 30th overall pick in the 2009 NFL draft.

Prior to National Signing Day, there were strong rumors that he would commit to Illinois but he chose to attend Rutgers instead.

That season, he had a major role in one of the biggest wins in school history, which was the 28–25 victory over Louisville.

[12][13] Coming into the 2008 season, Britt was named to the preseason All-Big East teams by numerous publications, including Phil Steele and Athlon Sports.

[22] On January 3, 2009, Britt announced he would forgo his senior season at Rutgers University and declare himself eligible for the 2009 NFL Draft.

[23] Britt had a solid NFL Combine performance, running a 4.56 40-yard dash, lifting 23 reps of 225 lbs on bench press, displaying a 37-inch vertical leap, 124.0 inch broad jump, and the 20-yard shuttle in 4.47 seconds.

[28] His first game against the Pittsburgh Steelers was solid as he caught four passes for 85 yards, including a 57-yard reception in a 13–10 loss.

[29] He scored his first touchdown on the receiving end of a Vince Young pass on November 23, 2009, against the Houston Texans in Week 11.

[30] On November 29, 2009, in Week 12, Britt caught a ten-yard game-winning touchdown pass in the back of the endzone from Young as time was expiring during a 20–17 victory over the Arizona Cardinals.

[32] On October 24, 2010, Kenny caught seven passes, three touchdowns and gained 225 yards in a 37–19 victory over the Philadelphia Eagles.

[37][38] Britt was suspended for the first game of the 2012 season due to numerous incidents involving police.

[48] In the 2016 season, Britt became the first Rams wide receiver to reach 1,000 yards since Torry Holt in 2007.

[60] On March 6, 2018, the Patriots decided to pick up Britt's second-year option, retaining him for the 2018 season.

[63] On April 12, 2011, Britt was arrested in New Jersey on three counts (including a felony) following an alleged car chase with police.