Headstrong yet aimless, Will Hunting has a genius-level IQ but chooses to work as a janitor at MIT. When he secretly solves highly difficult graduate-level math problems, his talents are discovered by Professor Gerald Lambeau, who decides to help the misguided youth reach his potential. When Will is arrested for attacking a police officer, Professor Lambeau makes a deal to get leniency for him if he gets court-ordered therapy. Eventually, therapist Dr. Sean Maguire helps Will confront the demons that are holding him back.

South Boston Irish bad boy Danny Quinn returns back home from New York and gets stuck between his pals, who are supported by one Irish mafia clan, and his family, which are members of another.