Humphrey Bogart as Billy Dannreuther

Jennifer Jones as Gwendolen Chelm

Gina Lollobrigida as Maria Dannreuther

Robert Morley as Peterson

Peter Lorre as Julius O'Hara

Edward Underdown as Harry Chelm

Ivor Barnard as Maj. Jack Ross

Marco Tulli as Ravello

Bernard Lee as Insp. Jack Clayton

Mario Perrone as Purser on SS Nyanga

Giulio Donnini as Administrator

Saro Urzì as Captain of SS Nyanga

Juan de Landa as Hispano-Suiza Driver

Aldo Silvani as Charles

Mimmo Poli as Barman (uncredited)

Peter Sellers as Billy Dannreuther (voice) (uncredited)

Manuel Serrano as Ahmed (uncredited)