Jonah Bobo's first film role was in the 2004 independent film, The Best Thief in the World. He co-starred opposite Christopher Walken and Josh Lucas in the 2004 drama Around the Bend, playing the youngest of a four-generation family. Jonah was subsequently cast in the fantasy film Zathura. Bobo's next role was in another independent film, Strangers with Candy, which opened on June 28, 2006.
Bobo played young Victor Mancini in the film adaptation of Chuck Palahniuk's novel Choke. He has also made an appearance on 30 Rock as a paparazzo named Ethan. His most recent work was on Roosevelt Island in the play Seussical Jr. at the Main Street Theatre and Dance Alliance. He was also on the fifth episode of Royal Pains. In 2007, he began attending Camp Tranquility located in Earlton, New York. There, he performed in the weekly performances, such as The Wizard of Oz.