George Formby as George Hepplewhite

Phyllis Calvert as Mary Wilson

Garry Marsh as Mendez

Romney Brent as Slim Selwyn

Bernard Lee as Oscar

Coral Browne as Iris

Helena Pickard as Oscar's Wife

Percy Walsh as Schwartz, Spy Chieftain

Diana Beaumont as Greta, Hotel Receptionist

Torin Thatcher as U-Boat Commander

Donald Calthrop as Frederick Strickland

Hal Gordon as Alf Arbuckle, Dinky Do

Johnnie Schofield as Solicitous Steward

Daniel Brown as Baker (uncredited)

Alec Clunes as Officer (uncredited)

Walter Fitzgerald as Dockside Policeman (uncredited)

Ian Fleming as Col. Harcourt (uncredited)

Jack Hobbs as Conway (uncredited)

James Knight as Passenger On SS Macaulay (uncredited)

Albert Lieven as German Radio Operator (uncredited)

Charles Paton as Simion (uncredited)

Lloyd Pearson as Hotel Manager (uncredited)

Bill Shine as Untipped Steward (uncredited)

Ronald Shiner as Musician (uncredited)

Ben Williams as Radio Operator On SS Macaulay (uncredited)

Ian Wilson as Parker, Dinky Do (uncredited)