Toni Collette
Patricia Herman
Michael Sheen
Dr. Slavkin O'Hara
Oprah Winfrey
Oprah
Aaron Abrams
Malcom's Dad / Nurse Stewart
Kate Hewlett
Alice O'Hara
Jason Spevack
Henry James Herman
Austin Macdonald
Brian the Bully
Jamie Johnston
Young Billy Herman
Frank Moore
Stan Herman
Mishu Vellani
Miss Abda
Kevin Hare
Delivery Room Doctor
Samantha Weinstein
Audrey O'Hara
Cameron Kennedy
Jimmy Herman
Paul Braunstein
Dr. Gunther Flowers
Sarah Orenstein
Mother Herman