Alec Guinness as Jim Wormold

Burl Ives as Dr. Hasselbacher

Maureen O'Hara as Beatrice Severn

Ernie Kovacs as Capt. Segura

Noël Coward as Hawthorne

Ralph Richardson as 'C'

Jo Morrow as Milly Wormold

Grégoire Aslan as Cifuentes

Paul Rogers as Hubert Carter

Raymond Huntley as General

Ferdy Mayne as Prof. Sanchez

Maurice Denham as Admiral

Joseph G. Prieto as Lopez

Duncan Macrae as MacDougal

Gerik Schjelderup as Svenson

Hugh Manning as Officer

Karl Stepanek as Dr. Braun

Maxine Audley as Teresa

Elisabeth Welch as Woman

Yvonne Buckingham as Woman

Rachel Roberts as Prostitute (uncredited)