 Karl MaldenDr. Marais | Dr. Marais |
 Claude DauphinInsp. Bonnard | Insp. Bonnard |
 Patricia MedinaJeanette | Jeanette |
 Steve ForrestProf. Paul Dupin | Prof. Paul Dupin |
 Allyn Ann McLerieYvonne (as Allyn McLerie) | Yvonne (as Allyn McLerie) |
 Anthony CarusoJacques the One-Eyed | Jacques the One-Eyed |
 Veola VonnArlette | Arlette |
 Dolores DornCamille | Camille |
 Merv GriffinGeorges Brevert | Georges Brevert |
 Paul RichardsRene the Knife-thrower | Rene the Knife-thrower |
 Rolfe SedanLeBon (as Rolphe Sedan) | LeBon (as Rolphe Sedan) |
 Erin O'Brien-MooreWardrobe Woman | Wardrobe Woman |
 Henry KulkyMaurice | Maurice |
| AAbdullah AbbasShow Spectator (uncredited) | Show Spectator (uncredited) |
 Rico AlanizGendarme (uncredited) | Gendarme (uncredited) |
 Fred AldrichBarfly (uncredited) | Barfly (uncredited) |
| MMonya AndreShow Spectator (uncredited) | Show Spectator (uncredited) |
| LLarry ArnoldGendarme (uncredited) | Gendarme (uncredited) |
 Richard AvondeVendor (uncredited) | Vendor (uncredited) |
 Baynes BarronCircus Manager (uncredited) | Circus Manager (uncredited) |
 Max BarwynConcierge (uncredited) | Concierge (uncredited) |
| HHerman BelmonteGendarme (uncredited) | Gendarme (uncredited) |
| JJoan BlairLodger (uncredited) | Lodger (uncredited) |
 Marie BlakeMarie (uncredited) | Marie (uncredited) |
 Nan BoardmanCamille's Mother (uncredited) | Camille's Mother (uncredited) |
| NNina BorgetTenant (uncredited) | Tenant (uncredited) |
 Chet BrandenburgSailor (uncredited) | Sailor (uncredited) |
 Paul BrinegarAngry Accuser in Street (uncredited) | Angry Accuser in Street (uncredited) |
 Virginia BrissacWell-Dressed Woman in Coach (uncredited) | Well-Dressed Woman in Coach (uncredited) |
| BBuck BuckoMurder Scene Spectator (uncredited) | Murder Scene Spectator (uncredited) |
