 James McAvoyDennis / Patricia / Hedwig / The Beast / Kevin Wendell Crumb / Barry / Orwell / Jade | Dennis / Patricia / Hedwig / The Beast / Kevin Wendell Crumb / Barry / Orwell / Jade |
 Anya Taylor-JoyCasey Cooke | Casey Cooke |
 Haley Lu RichardsonClaire Benoit | Claire Benoit |
 Jessica SulaMarcia | Marcia |
 Betty BuckleyDr. Karen Fletcher | Dr. Karen Fletcher |
 Izzie CoffeyFive-Year-Old Casey | Five-Year-Old Casey |
 Brad William HenkeUncle John | Uncle John |
 Sebastian ArcelusCasey's Father | Casey's Father |
 Neal HuffMr. Benoit | Mr. Benoit |
 Ukee WashingtonNews Anchor | News Anchor |
| AAnn WoodGame Show Enthusiast | Game Show Enthusiast |
| RRobert Michael KellyJoe | Joe |
 M. Night ShyamalanJai, Hooters Lover | Jai, Hooters Lover |
 Rosemary HowardKevin's Mother | Kevin's Mother |
| JJerome GallmanVince, Security Guard | Vince, Security Guard |
 Lyne ReneeAcademic Moderator | Academic Moderator |
| KKate JacobyDr. Fletcher's Patient | Dr. Fletcher's Patient |
 Peter PatrikiosTaxi Driver | Taxi Driver |
 Kash GoinsFlower Kiosk Worker | Flower Kiosk Worker |
 Roy James WilsonSecurity Guy with Dog | Security Guy with Dog |
 Christopher Lee PhilipsOlder Worker | Older Worker |
| JJulie PotterParamedic | Paramedic |
 Ameerah BriggsPolice Officer #1 | Police Officer #1 |
 Nakia DillardPolice Officer #2 | Police Officer #2 |
 Robin RiegerTelevision Reporter | Television Reporter |
 Emlyn McFarlandDiner Waitress | Diner Waitress |
 Dann FinkGame Show Contestant (voice) | Game Show Contestant (voice) |
 Bruce WinantGame Show Host (voice) | Game Show Host (voice) |
 Bruce WillisDavid Dunn (uncredited) | David Dunn (uncredited) |
 Kim DirectorHannah (uncredited) | Hannah (uncredited) |
