- Mervyn Johns
- No. 23 (Mr. Davis)
- John Chandos
- No. 16
- Nova Pilbeam
- Beppie Leemans
- Reginald Tate
- Maj. Richards
- Stephen Murray
- Mr. Barratt
- Geoffrey Hibbert
- Pte. John
- Philip Friend
- Lieut. Cummings
- Phyllis Stanley
- Miss Clare - the Dancer
- Mary Clare
- Mrs. 'Ma' Webster
- Basil Sydney
- Naval Captain
- Joss Ambler
- Mr. Vemon
- Brefni O'Rorke
- The Brigadier Blunt
- Alexander Field
- Pte. Durnford
- David Hutcheson
- Intelligence Officer
- Jack Hawkins
- Brigade Major Harcourt
- Frederick Leister
- Colonel
- Torin Thatcher
- German General
- Charles Victor
- Neutral Seaman - Irish Joe
- Richard Norris
- Pvt. Jimmy
- Guy Maas
- The Frenchman - Captain Mercier
- Thora Hird
- The A.T.S. Girl
- Basil Radford
- Careless Talker on Train (last scene)
- Naunton Wayne
- Careless Talker on Train (last scene)
- J. Edgar Hoover
- Narrator (Prologue and Epilogue) (US version)
- Johnnie Schofield
- Lance-Corporal
- Frank Allenby
- Wing-Comdr. Kenton
- Worcestershire Regiment
- Principal Players
- Victor Beaumont
- German Colonel
- Mark Daly
- Corporal on Train
- Ian Fleming
- Naval Officer
- Hal Gordon
- Builder's Labourer
- Cameron Hall
- Army Clerk at Ordinance Factory Dance
- James Knight
- Sailor on Train
- Agnes Lauchlan
- Mrs. Taylor (manageress of The White Hart hotel)
- Mary Malcolm
- Kenton's Secretary
- Owen Reynolds
- Dentist
- Charles Rolfe
- Mr. Palmer
- Jack Sharp
- Warden
- George Street
- Inspector Jolly
- Guy Verney
- Soldier in Buffet Car
- William Walton
- Soldier at Security Briefing
- H Victor Weske
- Ted
- John Williams
- General Cooper
