- Cary Grant as John Robie ("The Cat")
- Grace Kelly as Frances Stevens
- Jessie Royce Landis as Jessie Stevens
- John Williams as H. H. Hughson
- Charles Vanel as Monsieur Bertani
- Brigitte Auber as Danielle Foussard
- Jean Martinelli as Foussard, Danielle's father
- Georgette Anys as Germaine, housekeeper
- René Blancard as Commissaire Lepic (uncredited)
Alfred Hitchcock makes his signature cameo approximately ten minutes in as a bus passenger sitting next to Cary Grant.
Despite Brigitte Auber's character being referred to as a "girl" or "teenager", compared to Grace Kelly's supposedly more mature character, Auber was actually 26 years old at the time of filming and more than a year and a half older than Kelly.