James McAvoy
as Kevin Wendell Crumb

Anya Taylor-Joy
as Casey Cooke

Betty Buckley
as Karen Fletcher

Haley Lu Richardson
as Claire Benoit

Jessica Sula
as Marcia

Izzie Coffey
as Five-Year-Old Casey

Brad William Henke
as Uncle John

Sebastian Arcelus
as Casey's Father

Neal Huff
as Mr. Benoit

Ukee Washington
as News Anchor

Ann Wood
as Game Show Enthusiast

Robert Michael Kelly
as Joe

M. Night Shyamalan
as Jai, Hooters Lover

Rosemary Howard
as Kevin's Mother

Jerome Gallman
as Vince, Security Guard

Lyne Renee
as Academic Moderator

Kate Jacoby
as Dr. Fletcher's Patient

Peter Patrikios
as Taxi Driver

Kash Goins
as Flower Kiosk Worker

Roy James Wilson
as Security Guy with Dog

Christopher Lee Philips
as Older Worker

Julie Potter
as Paramedic

Ameerah Briggs
as Police Officer #1

Nakia Dillard
as Police Officer #2

Robin Rieger
as Television Reporter

Emlyn McFarland
as Diner Waitress

Dann Fink
as Game Show Contestant (voice)

Bruce Winant
as Game Show Host (voice)

Bruce Willis
as David Dunn (uncredited)

Kim Director
as Hannah (uncredited)

Robert Bizik
as Bar Patron (uncredited)

Junnie Lopez
as Geraldo (uncredited)

Steven Dennis
as Dan at Next Table (uncredited)

Matthew Nadu
as Waiter (uncredited)

James Robinson Jr.
as Claire's Party Guest (uncredited)

John Mitchell
as EMT (uncredited)

Aleksandra Svetlichnaya
as Pedestrian (uncredited)

Colin Campbell
as Boy in Park (uncredited)

John Jillard Sr.
as Homeland Security (uncredited)

Vincent Riviezzo
as Detective (uncredited)

Gary Ayash
as Restaurant Patron (uncredited)