Two sets of identical twins are accidentally switched at birth. One pair, Phillipe and Pierre DeSisi, are aristocratic and haughty, while the other, Charles and Claude Coupé, are poor and dim-witted. On the eve of the French Revolution, both sets find themselves entangled in palace intrigue.
| Actor | Role |
|---|---|
 Gene WilderClaude / Philippe | Claude / Philippe |
 Donald SutherlandCharles / Pierre | Charles / Pierre |
 Hugh GriffithKing Louis | King Louis |
 Jack MacGowranJacques | Jacques |
 Billie WhitelawQueen Marie | Queen Marie |
 Victor SpinettiDuke d'Escargot | Duke d'Escargot |
 Ewa AulinChristina | Christina |
 Helen FraserMimi | Mimi |
 Rosalind KnightHelene de Sisi | Helene de Sisi |
 Harry FowlerMarcel | Marcel |
 Murray MelvinBlind Man | Blind Man |
| KKen ParryDr. Boileau | Dr. Boileau |
 Orson WellesThe Narrator | The Narrator |
| MMaxwell ShawDuke de Sisi | Duke de Sisi |
 Jacques MauryLt. Sorel | Lt. Sorel |
 Graham StarkAndre Coupe | Andre Coupe |
| BBarry LoweThe Sergeant | The Sergeant |
 George A. CooperDr. Duval | Dr. Duval |
| MMichael RothwellPaul Duval | Paul Duval |
 Denise CoffeyAnne Duval | Anne Duval |