- Richard George
- Kommandant Bernsdorff (The U-Boat Crew)
- Eric Portman
- Lieutenant Hirth (The U-Boat Crew)
- Raymond Lovell
- Lieutenant Kuhnecke (The U-Boat Crew)
- Niall MacGinnis
- Vogel (The U-Boat Crew)
- Peter Moore
- Kranz (The U-Boat Crew)
- John Chandos
- Lohrmann (The U-Boat Crew)
- Basil Appleby
- Jahner (The U-Boat Crew)
- Laurence Olivier
- Johnnie, the Trapper (The Canadians)
- Finlay Currie
- The Factor (The Canadians)
- Ley On
- Nick, the Eskimo (The Canadians)
- Anton Walbrook
- Peter (The Canadians)
- Glynis Johns
- Anna (The Canadians)
- Charles Victor
- Andreas (The Canadians)
- Frederick Piper
- David (The Canadians)
- Leslie Howard
- Philip Armstrong Scott (The Canadians)
- Tawera Moana
- George, the Indian (The Canadians)
- Eric Clavering
- Art (The Canadians)
- Charles Rolfe
- Bob (The Canadians)
- Raymond Massey
- Andy Brock (The Canadians)
- Theodore Salt
- A United States Customs Officer
- O.W. Fonger
- A United States Customs Officer
- Elisabeth Bergner
- Anna (replaced by Glynis Johns)
- George Alexander
- Cameo Appearance
- Robert Beatty
- RCMP Mountie in Alberta
- Eric Berry
- Nazi Radio Announcer
- Gron Davies
- Officer on Submarine
- Leslie Falardeau
- Aviator on Seaplane
- Toni Gable
- Hutterite Woman
- Lionel Grose
- Undetermined Secondary Role
- Jack Hynes
- Aviator on Seaplane
- Stuart Latham
- Second Nazi Radio Announcer
- Norman Luxton
- Man in Fringed Jacket on Balcony at Banff Indian Day
- Vincent Massey
- Prologue Narrator
- Percy Parsons
- Hi-Jacked Canadian Motorist
- Gerry Wilmot
- Canadian Radio Announcer
