Answer: Matt Damon
'Good Will Hunting' starred Matt Damon, Ben Affleck, Robin Williams, Minnie Driver and Stellan Skarsgård, but it was Damon who played the title role. The film, which was first released in 1997, was directed by Gus Van Sant. It told the story of a genius janitor named Will Hunting who worked in a university, but had the intelligence to solve a series of difficult mathematical problems set out by a Professor Lambeau (Skarsgård). When Lambeau discovered that it was the janitor rather than one of his students who solved the problems, he enlisted a therapist (Williams) to help Hunting overcome issues related to the abuse he had suffered as a child and pursue a relationship with an English girl named Skylar (Driver). Ben Affleck, who co-wrote the film with Matt Damon, played one of Hunting's friends.
'Good Will Hunting' netted Williams an Academy Award for Best Supporting Actor.