* Carol Lynley as Anne Lake
* Keir Dullea as Detective Sergeant Stevens
* Laurence Olivier as Mr. Alistair Lake
* Martita Hunt as Miss Ruth, the landlady
* Anna Massey as the mysterious neighbor
* Noël Coward as the seemingly-helpful neighbor
* Robin Bailey as a character with a strong resemblance to Anne's lost daughter, Bunny
* Stephen Boyd as an actor who meets Anne
* Ingrid Bergman as the psychiatrist who speaks to Anne
The film has a number of supporting actors who play smaller, but memorable, roles.