James McAvoy
Dennis / Patricia / Hedwig / The Beast / Kevin Wendell Crumb / Barry / Orwell / Jade
Anya Taylor-Joy
Casey Cooke
Haley Lu Richardson
Claire Benoit
Jessica Sula
Marcia
Betty Buckley
Dr. Karen Fletcher
Izzie Coffey
Five-Year-Old Casey
Brad William Henke
Uncle John
Sebastian Arcelus
Casey's Father
Neal Huff
Mr. Benoit
Ukee Washington
News Anchor
Ann Wood
Game Show Enthusiast
Robert Michael Kelly
Joe
M. Night Shyamalan
Jai, Hooters Lover
Rosemary Howard
Kevin's Mother
Jerome Gallman
Vince, Security Guard
Lyne Renee
Academic Moderator
Kate Jacoby
Dr. Fletcher's Patient
Peter Patrikios
Taxi Driver
Kash Goins
Flower Kiosk Worker
Roy James Wilson
Security Guy with Dog
Christopher Lee Philips
Older Worker
Julie Potter
Paramedic
Ameerah Briggs
Police Officer #1
Nakia Dillard
Police Officer #2
Robin Rieger
Television Reporter
Emlyn McFarland
Diner Waitress
Dann Fink
Game Show Contestant (voice)
Bruce Winant
Game Show Host (voice)
Bruce Willis
David Dunn (uncredited)
Kim Director
Hannah (uncredited)
Robert Bizik
Bar Patron (uncredited)
Junnie Lopez
Geraldo (uncredited)
Steven Dennis
Dan at Next Table (uncredited)
Matthew Nadu
Waiter (uncredited)
James Robinson Jr.
Claire's Party Guest (uncredited)
John Mitchell
EMT (uncredited)
Aleksandra Svetlichnaya
Pedestrian (uncredited)
Colin Campbell
Boy in Park (uncredited)
John Jillard Sr.
Homeland Security (uncredited)
Vincent Riviezzo
Detective (uncredited)
Gary Ayash
Restaurant Patron (uncredited)