 Valentina CorteseMaria Brentano / Brent / Lena Collins | Maria Brentano / Brent / Lena Collins |
 Serge ReggianiLouis Balan | Louis Balan |
 Audrey HepburnNora Brentano | Nora Brentano |
 Megs JenkinsPenny | Penny |
 Irene WorthMiss Jackson | Miss Jackson |
 Reginald TateInspector Eliot | Inspector Eliot |
| CCharles GoldnerAnselmo | Anselmo |
| AAngela FouldesNora Brentano as a child | Nora Brentano as a child |
 Simone SilvaUndetermined (Minor Role - Paris Sequence) (uncredited) | Undetermined (Minor Role - Paris Sequence) (uncredited) |
| NNorman WilliamsSergeant Newcome | Sergeant Newcome |
 Michael ShepleyManager of the British Pavilion | Manager of the British Pavilion |
 Athene SeylerMrs. Reginald Kellick | Mrs. Reginald Kellick |
 Sydney TaflerSyd Burnett | Syd Burnett |
 Geoffrey HibbertSteenie | Steenie |
| JJohn RuddockDaly | Daly |
| MMichael AllanRodd | Rodd |
| JJohn FieldFedor Luki | Fedor Luki |
| HHugo SchusterGeneral Galbern | General Galbern |
| LLionel HarrisFrack | Frack |
| RRollo GambleBentley | Bentley |
 John PenroseBill | Bill |
 John ChandosJohn | John |
 Michael RipperCharlie | Charlie |
 John Louis MansiMember of Paris Committee | Member of Paris Committee |
 John GabrielMember of Paris Committee | Member of Paris Committee |
| OOlga LandiakMember of Paris Committee | Member of Paris Committee |
 Frederick SchillerGalbern's Bodyguard | Galbern's Bodyguard |
| PPhaedros AntonioGalbern's Bodyguard | Galbern's Bodyguard |
| GGaston RicherQueval | Queval |
| DDerek ElphinstonePlain Clothes Man | Plain Clothes Man |
