Matt Damon
Will Hunting
Robin Williams
Sean Maguire
Ben Affleck
Chuckie Sullivan
Stellan Skarsgård
Gerald Lambeau
Minnie Driver
Skylar
Casey Affleck
Morgan O'Mally
Cole Hauser
Billy McBride
Vik Sahay
MIT Student
John Mighton
Tom
Rachel Majorowski
Krystyn
Colleen McCauley
Cathy
Matt Mercier
Barbershop Quartet #1
Ralph St. George
Barbershop Quartet #2
Rob Lynds
Barbershop Quartet #3
Dan Washington
Barbershop Quartet #4
Alison Folland
MIT Student
Derrick Bridgeman
MIT Student
Shannon Egleson
Girl on Street
Rob Lyons
Carmine Scarpaglia
Steven Kozlowski
Carmine Friend #1
Jennifer Deathe
Lydia
Scott William Winters
Clark
Philip Williams
Head Custodian
Patrick O'Donnell
Assistant Custodian
Kevin Rushton
Courtroom Guard
Jimmy Flynn
Judge Malone
Joe Cannon
Prosecutor
Ann Matacunas
Court Officer
George Plimpton
Psychologist
Francesco Clemente
Hypnotist
Jessica Morton
Bunker Hill Student
Barna Moricz
Bunker Hill Student
Libby Geller
Toy Store Cashier
Chas Lawther
MIT Professor
Richard Fitzpatrick
Timmy
Frank Nakashima
Executive #1
Chris Britton
Executive #2
David Eisner
Executive #3
Bruce Hunter
NSA Agent
Robert Talvano
NSA Agent #2
James Allodi
Security Guard
Michael Arthur
Reunion Guest (uncredited)
Christian Harmony
Student (uncredited)
Riva Di Paola
MIT Student (uncredited)
Harmony Korine
Hervé (uncredited)
Thomas Lundy
Waiter (uncredited)
Paul McGillicuddy
Race Track Fan (uncredited)
Daniel Olsen
MIT Student (uncredited)
Stephen L'Heureux
Bartender (uncredited)