| David Niven | | Sir Charles Litton |
| Peter Sellers | | Insp. Jacques Clouseau |
| Robert Wagner | | George Litton |
| Capucine | | Simone Clouseau |
| Brenda de Banzie | | Angela Dunning |
| Colin Gordon | | Tucker |
| John Le Mesurier | | Defence Barrister |
| James Lanphier | | Saloud |
| Guy Thomajan | | Artoff |
| Michael Trubshawe | | Felix Townes |
| Riccardo Billi | | Aristotle Sarajos |
| Meri Welles | | Monica Fawn |
| Martin Miller | | Pierre Luigi - Photographer |
| Fran Jeffries | | Greek 'cousin' |
| Claudia Cardinale | | The Princess |
| John Bartha | | Big Joe |
| William Bryant | | Policeman |
| Aristide Catoni | | Costume Party Guest |
| Enrico Cesaretti | | Cortina d'Ampezzo Holiday Guest |
| Franz Colangeli | | Cortina d'Ampezzo Holiday Guest |
| Andrea Esterhazy | | Holiday Guest at Cortina d'Ampezzo |
| Mario Fabrizi | | Hotel Manager |
| Umberto Fantoni | | Cortina d'Ampezzo Holiday Guest |
| Giuliana Farnese | | Holiday Guest at Cortina d'Ampezzo |
| Ferruccio Fregonese | | Trial Spectator |
| Philip H. Lathrop | | Inspector Chasing Simone |
| Romano Milani | | Policeman |
| Vezio Natili | | Cortina d'Ampezzo Holiday Guest |
| Mario Pascucci | | Cortina d'Ampezzo Holiday Guest |
| Attilio Pelegatti | | Cortina d'Ampezzo Holiday Guest |
| Francesco Tensi | | Lord Cravenwood |
| Eugene Walter | | Hotel Manager |
| Irina Wassilchikoff | | Cortina d'Ampezzo Holiday Guest |
| Walter Williams | | Hotel Bartender |
| Milena Zampana | | Cortina d'Ampezzo Holiday Guest |
| Wael Zuaiter | | Waiter |