On April 2, 2009, Bennett’s former teammate at Vanderbilt during the 2005 season, Pro Bowl quarterback Jay Cutler was acquired by the Bears via a trade with the Denver Broncos. Bears head coach Lovie Smith said Bennett would be given “every opportunity” to win a spot as a starting receiver alongside Devin Hester in 2009. Bennett did just that during the course of mandatory mini-camp and training camp, as he showed an ability to make tough grabs in traffic and a willingness to go over the middle. Bennett and Cutler quickly regained the chemistry they shared on and off the field during their college years playing together at Vanderbilt. During that offseason, Bennett also changed his number from 85 to 80. (He tried to obtain his original college number 10, but since NFL rules prohibit players from changing numbers in the 80s to numbers in the 10s, he settled for 80 as it reminded him of Jerry Rice.)

In Week 2 against the Saints, Bennett was injured, and did not return to the game. This eventually created controversy in 2012 after the Saints were caught using a bounty program. In Week 9, Bennett’s return helped the Bears defeat the Eagles with a touchdown pass. However, after the Eagles game, Bennett was fined $5,000 for wearing bright orange cleats. After he wore the shoes again against the Detroit Lions the following week, the league told him that wearing the shoes again will result in an increase of $5,000 in his fines. The league later informed him that wearing the cleats a third consecutive time will result in him being ejected and the Bears being penalized. After wearing the cleats in 2012 against the Lions, the league fined him once again. On December 12, Bennett was signed to a four-year extension, keeping him with the Bears through 2014.

In Week 17 against the Lions, Bennett caught five passes for 109 yards, a career best, and one touchdown. As a result, Bennett became the first Bears receiver besides Brandon Marshall to compile more than 80 yards in a game in 2012.

In 2012, Bennett held “The Prime Experience with Earl Bennett” at III Forks to help benefit his charity, “Earl Bennett’s Legends for Literacy”.

In 2013, Bennett caught 32 passes for 243 yards and a career-high four touchdowns. Bennett missed the 2013 week 17 game against the Green Bay Packers after his brother’s death.

On March 18, 2014, Bennett was released by the Bears after refusing to have his salary reduced.

On May 14, 2014, Bennett signed with the Cleveland Browns. On June 17, 2014, his contract was terminated by the Browns.

In January 2015, Bennett returned to Vanderbilt University to complete his educational studies degree from Peabody College of Education and Human Development.