Kit Harington as John F. Donovan

Natalie Portman as Sam Turner

Jacob Tremblay as Rupert Turner

Susan Sarandon as Grace Donovan

Kathy Bates as Barbara Haggermaker

Ben Schnetzer as Rupert Turner (21 y.o.)

Thandiwe Newton as Journalist

Jared Keeso as James Donovan

Chris Zylka as Will Jefford Jr.

Amara Karan as Miss Kureshi

Emily Hampshire as Amy Bosworth

Michael Gambon as Man in Diner

Sarah Gadon as Liz Jones

Susan Almgren as Aunt Faith

Jane Wheeler as Aunt Anne

Craig Eldridge as Uncle Patrick

Lukas Rolfe as Cedric

Ari Millen as Big Billy

Gijs Blom as Rupert's Boyfriend

Rob Baker as Late Night Show Host

Ellen David as Adam's Mother

Pat Kiely as Director

Anne Mroczkowski as News Anchor

James Marchant as Police Officer

Suzanne Virdee as Female Anchor

Guenièvre Sandré as Barmaid

Sangita Patel as Journalist #1

Hamza Haq as Journalist #2

Matthew Raudsepp as Hellsome High Actor

Michael Brunet as Cashier

Michael Dozier as Lawyer #1

Harvey Diamond as Lawyer #2

Pierre-Luc Lafontaine as Fan in the Club

Vincent Messina as Young Fan

Anthony Luigi Aguiar as Young Fan

Cassie Luk as Young Fan

Hannah Morgan Lord as Young Fan

Rebecca Windheim as Young Fan

Dakota Jamal Wellman as Eric (uncredited)

Leni Parker as Bonnie (uncredited)

Katy Breier as Trish (uncredited)

Alison Louder as Hellsome High Actress (uncredited)

Brent Skagford as Editor #1 (uncredited)

Carolyn Fe as Porter (uncredited)

Connor McMahon as Intern (Sasha) (uncredited)

Holly Bernier as Journalist (uncredited)

Sam Taylor Buck as Young Daniel (uncredited)

Daniel Murphy as Editor #2 (uncredited)