Franco, who started out on TV's "Freaks and Geeks" and in the bio-pic "James Dean," has co-starred in the "Spider-Man" trilogy and appeared in films like "Sonny," "City by the Sea," "The Dead Girl" and "Flyboys."
He reportedly graduated from the University of California in Los Angeles last month at the age of 30, after taking English literature classes for years.
"I am going back to school because I love being around people who are interested in what I'm interested in," Franco told the New York Daily News. "That is the best way to learn. For me, being able to act in movies is not having it all. I am interested in other things, and I take my interests seriously. Thus, I'm back in school."