| Sylvina Lawrence / Martina Lawrence | 伊丽莎白·伯格纳
 | |
| Alan MacKenzie | 迈克尔·雷德格瑞夫
 | |
| Thomas E. Lawrence | Wilfrid Lawson | |
| Aunt Helen (as Mabel Terry Lewis) | Mabel Terry-Lewis | |
| Morgan | Richard Ainley | |
| Garrett | Kenneth Buckley | |
| Old Pauliac (as Danielle Mendaille) | Daniel Mendaille | |
| Doctor | Pierre Juvenet | |
| Nurse | Stella Arbenina | |
| Maturin | Kaye Seeley | |
| Police Supt. Demangeon | Ernest Ferny | |
| Clerk | Cot D'Ordan | |
| Eileen (Sylvina's maid) | Dorice Fordred | |
| Cook | Annie Esmond | |
| Karal Anderson | Clement McCallin | |
| Prof. Bardesley | Oliver Johnston | |
| British Minister | Roy Russell | |
| Mayor | Homer Regus | |
| 'Boomsie' | An Old English Sheepdog | |
| (uncredited) | Davina Carid | |
| (uncredited) | Cyril Chamberlain | |
| (uncredited) | O.B. Clarence | |
| (uncredited) | Dorothy Dewhurst | |
| (uncredited) | Cyril Horrocks | |
| (uncredited) | Fewlass Llewellyn | |
| (uncredited) | John Lloyd | |
| (uncredited) | Gayenne Michaeldze | |
| (uncredited) | Paulette Preney | |
