Ramon Novarro
— Archduke Paul 'Gustl' Gustave
Evelyn Laye
— Elizabeth Katherine Anne 'Lisl' Gluck
Charles Butterworth
— Willy Fitch
Una Merkel
— Fanni Kerner
Edward Everett Horton
— Baron Szereny
Donald Cook
— Toni Berngruber
Henry Stephenson
— Emperor Franz Josef
Rosalind Russell
— Countess Zarika Rafay
Herman Bing
— Nepomuk
Florine Baile
— Undetermined Role (uncredited)
Max Barwyn
— Max - the Waiter (uncredited)
Art Berry Sr.
— Undetermined Role (uncredited) (unconfirmed)
Albert Conti
— Mueller (uncredited)
George Davis
— Milkman (uncredited)
Carlos De Valdez
— Adjutant (uncredited)
Chico De Verdi
— Undetermined Role (uncredited) (unconfirmed)
Billy Dooley
— Coronetist (uncredited)
Elspeth Dudgeon
— Duchess of Reidheim (uncredited)
Kay English
— Undetermined Role (uncredited)
Charles Judels
— Riccardi (uncredited)
Edith Kingdon
— Dowager at Opera House (uncredited)
Michael Mark
— Messenger from Restaurant (uncredited)
Torben Meyer
— Adjutant (uncredited)
Harry 'Snub' Pollard
— Drummer (uncredited)
Christian Rub
— Café Proprietor (uncredited)
Charles Unger
— Undetermined Role (uncredited)
Gustav von Seyffertitz
— Ambassador (uncredited)