Ben Affleck
Charlie Maguire
Tye Sheridan
JR Maguire
Daniel Ranieri
Young JR Maguire
Lily Rabe
Dorothy Maguire
Christopher Lloyd
Grandpa Maguire
Max Martini
The Voice, JR's father
Rhenzy Feliz
Wesley
Briana Middleton
Sidney
Max Casella
Chief
Sondra James
Grandma Maguire
Michael Braun
Bobo
Matthew Delamater
Joey D
Ivan Leung
Jimmy
Danielle Ranieri
Aunt Ruth
Kate Avallone
Kathy
Mark Boyett
Sidney's Dad
Quincy Tyler Bernstine
Sidney's Mom
Ezra Knight
Professor Van Dyke
David Carl
School Psychologist
Shannon Collis
Pat
Keira Jo Lassor
Kathy's Daughter
Jennifer C. Johnson
Mrs. Williams
Michael Steven Costello
NYT Editor
Kate Middleton
NYT Personnel Woman
Jackson Damon
NYT Copyboy
Caroline Bergwall
NYT Copygirl
Daniel Washington
Officer James
Jenny Eagan
Chief's Wife
Steve Gagliastro
Other Customer
Annabella Valle
Aunt Ruth's Kid #1
Clara Kelly
Aunt Ruth's Kid #2
Meara Mahoney Gross
Aunt Ruth's Kid #3
Ron Livingston
Future JR Maguire (voice only)
Jack Baumrind
Kid in Classroom (uncredited)
Julia Bechler
Dickens Bar Regular (uncredited)
Keith R Beck
Yale Student (uncredited)
Alissa Bourne
Dickens Bar Patron (uncredited)