Bell was previously known for her appearances on TV's Workaholics and Eastbound & Down.
"Jillian makes me want to quit show business and realize I am a complete fraud because she is the funniest person I have ever met in my life," Hill declared with a laugh, while talking to reporters during a recent round-table interview in New York.
"When I improvise with her... I'd never had that feeling [before working with her] where I am like, 'You're thinking of what I am going to think to say, but you are saying it quicker and phrased better than I would.' We were all blown away by her," Hill recalled.
"I think she is an absolute star. I think part of the joy of producing a movie is you are in the room when people walk in and you get to say, 'Oh, wow, we get to put a spotlight on this person that maybe hasn't had the spotlight before.' And that's what I think this movie is for her. I think she is going to get tons of other movies from this."
22 Jump Street, the follow-up to 2012's 21 Jump Street, is in theaters now. The sequel follows two cops [Hill and Channing Tatum] who go undercover at a college to try to take down a drug ring. Bell plays the no-nonsense, disapproving roommate of Hill's character's girlfriend, who is played by Amber Stevens.