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)

Megan Park as Laura (uncredited)