Kenan has starred in several films including Good Burger, based on the All That sketch of the same name, and Fat Albert, in which he played the title character. He has also had supporting roles in the movies Heavyweights, D2: The Mighty Ducks, Love Don't Cost a Thing, Barbershop 2: Back in Business, and Snakes on a Plane. Kenan had a recurring role on The Steve Harvey Show as Junior, with co-star Kel Mitchell. Recently, he returned to Nickelodeon for the show The Mighty B! as the voice of Rocky Rhodes.

In 2009, Thompson was a regular voice actor in the Fox cartoon series, Sit Down, Shut Up. He was voice acting principal, “Sue Sezno,” who, as evidenced by her last name, always says no. The series premiered on April 19, 2009, but was cancelled after only four episodes due to low ratings. Thompson provided the voice for the LeBron James puppet in Nike's MVP “Most Valuable Puppets” commercials, which were produced to be shown throughout the 2009 NBA Playoffs. Thompson also guest starred on the USA Network TV show Psych, Season 4's “High Top Fade Out” (episode 7). He played an estranged college singing buddy of the character Gus.