Logan Lerman

as Charlie

Emma Watson

as Sam

Ezra Miller

as Patrick

Mae Whitman

as Mary Elizabeth

Kate Walsh

as Mother

Dylan McDermott

as Father

Melanie Lynskey

as Aunt Helen

Nina Dobrev

as Candace

Johnny Simmons

as Brad

Joan Cusack

as Dr. Burton

Paul Rudd

as Mr. Anderson

Nicholas Braun

as Ponytail Derek

Reece Thompson

as Craig

Patrick de Ledebur

as Senior Bully

Brian Balzerini

as Linebacker

Tom Kruszewski

as Nose Tackle

Julia Garner

as Susan

Tom Savini

as Mr. Callahan

Emily Marie Callaway

as Mean Freshman Girl

Chelsea Zhang

as Shakespeare Girl

Jesse Scheirer

as Freshman Boy

Justine Nicole Schaefer

as Twin Girl #1

Julie Marie Schaefer

as Twin Girl #2

Leo Miles Farmerie

as 7-Year-Old Charlie

Isabel Muschweck

as 9-Year-Old Candace

Adam Hagenbuch

as Bob

Erin Wilhelmi

as Alice

Jordan Paley

as Rocky MC

Zane Holtz

as Chris

Timothy Breslin

as Policeman

Mark McClain Wilson

as Emergency Room Policeman

Atticus Cain

as Emergency Room Doctor

Stacy Chbosky

as Young Mom

Dihlon McManne

as Priest

Laurie Klatscher

as School Principal

Landon Pigg

as Peter

Jennifer Enskat

as Sam's Mom

William L. Thomas

as Patrick's Dad

Morgan Wolk

as Candace's Friend

Joe Fishel

as Father of Twin Girls (uncredited)