Brie Larson
as Ma

Jacob Tremblay
as Jack

Joan Allen
as Nancy

Sean Bridgers
as Old Nick

Tom McCamus
as Leo

William H. Macy
as Robert

Cas Anvar
as Dr. Mittal

Amanda Brugel
as Officer Parker

Wendy Crewson
as Talk Show Hostess

Joe Pingue
as Officer Grabowski

Sandy McMaster
as Veteran

Matt Gordon
as Doug

Zarrin Darnell-Martin
as Attending Doctor

Jee-Yun Lee
as News Anchor

Randal Edwards
as Lawyer

Justin Mader
as FBI Agent

Ola Sturik
as Reporter #1

Rodrigo Fernandez-Stoll
as Reporter #2

Rory O'Shea
as Reporter #3

Kate Drummond
as Neighbour

Jack Fulton
as Jack's Friend

Chantelle Chung
as Clerk (uncredited)

Brad Wietersen
as TV Crewman (uncredited)

Graeme Potts
as TV Cameraman (uncredited)

Katelyn Wells
as Teenage Girl (uncredited)

Celeste Bruno
as Heather Noelle (uncredited)