Audrey Hepburn (Princess Ann), Gregory Peck (Joe Bradley), Eddie Albert (Irving Radovich), Hartley Power (Mr. Hennessy), Harcourt Williams (Ambassador), Margaret Rawlings (Countess Vereberg), Tullio Carminati (Gen. Provno) more..., Paolo Carlini (Mario Delani), Claudio Ermelli (Giovanni), Paola Borboni (Charwoman), Alfredo Rizzo (Cab driver), Laura Solari (Hennessy's Secretary), Gorella Gori (Shoe Seller), Armando Annuale (Admiral Dancing with Princess (uncredited)), Maurizio Arena (Young Boy with Car (uncredited)), Gildo Bocci (Flower Seller (uncredited)), Andrea Esterhazy (Embassy Aide (uncredited)), George Higgins (Correspondent at Poker Game (uncredited)), Richard McNamara (Correspondent at Poker Game (uncredited)), Luigi Moneta (Old Man Dancing with Princess (uncredited)), Piero Pastore (Faceless Man on the Barge (uncredited)), Mimmo Poli (Worker Hugging the Three Out Side Police Station (uncredited)), Giuliano Raffaelli (Faceless Man on the Barge (uncredited)), Carlo Rizzo (Police Official (uncredited)), Gianna Segale (Girl at Cafe Waving at Irving (uncredited)), Dianora Veiga (Girl at Cafe Waving at Irving (uncredited)), Marco Tulli (Pallid Young Man Dancing with Princess (uncredited)), Tania Weber (Francesca - Irving's Model (uncredited)), Catherine Wyler (Schoolgirl (uncredited)), Nadia Balabine (Woman of Importance Watching the Military Parade (uncredited)), Silvio Bagolini (Undetermined Role (uncredited)), Alfred Browne (Correspondent at Poker Game (uncredited)), Franco Corsaro (Undetermined Role (uncredited)), John Cortay (Correspondent at Poker Game (uncredited)), Julián Cortés Cavanillas (Julian Cortes Cavanillas of 'ABC Madrid' (uncredited)), Vittoria Crispo (Undetermined Role (uncredited)), Ugo De Pascale (Embassy Aide (uncredited)), Giovanni Fostini (Correspondent at Poker Game (uncredited)), Paul Gary (Undetermined Role (uncredited)), Sidney Gordon (Correspondent at Poker Game (uncredited)) and others.

Ian McLellan Hunter (Screenplay), John Dighton (Screenplay), William Wyler (Producer), Georges Auric (Original Music Composer), Henri Alekan (Director of Photography), Robert Swink (Editor), Hal Pereira (Art Direction) more..., Edith Head (Costume Design), Joseph de Bretagne (Sound Designer), Lester Koenig (Associate Producer), Walter H. Tyler (Art Direction), Anna Cristofani (Hairstylist), Herbert Coleman (Assistant Director), Bernard Vorhaus (Assistant Director), Italo Tomassi (Set Designer), Enzo Barboni (Camera Operator), Robert Belcher (Assistant Editor), Leo Shuken (Orchestrator), Joseph de Bretagne (Sound Recordist), Dalton Trumbo (Screenplay), Dalton Trumbo (Story), Franz Planer (Director of Photography), Alberto De Rossi (Makeup Supervisor), Wally Westmore (Makeup Supervisor), Robert Wyler (Associate Producer), Ian McLellan Hunter (Story), Luciano Sacripanti (Art Direction), Charles Woolstenhulme (Unit Manager), Maurizio Lodi-Fè (Unit Manager), Elso Valentini (Props), Vittorio Valentini (Props), Elide Morett (Stunt Double), Francesco Brescini (Gaffer), Bud Fraker (Still Photographer), Enzo Zocchi (Gaffer), Annalisa Nasalli-Rocca (Wardrobe Master), Franco Salvi (Wardrobe Master), Victor Young (Additional Music), Hazel Swift (Script Supervisor), Ennio Flaiano (Script Editor) and others.