According to Deadline, the actor will star as Eric, a popular high school drug dealer who becomes the target of two undercover agents played by Hill and Channing Tatum.
It has also been claimed that original 21 Jump Street star Johnny Depp will make a cameo appearance in the film.
Franco, brother of 127 Hours actor James Franco, has had supporting roles in a number of films, including Superbad and last year's Ben Stiller comedy Greenberg .
Franco will next be seen opposite Colin Farrell, Anton Yelchin and Toni Collette in DreamWorks' remake of the '80s horror comedy Fright Night
Sony Pictures is expected to begin production on 21 Jump Street this summer.