Fredric March
Marcus Superbus - Prefect of Rome
Charles Laughton
Emperor Nero Claudius Caesar
Henry Brandon
Colosseum Spectator (uncredited)
John Carradine
Christian Martyr / Gladiator Leader / Voice in Coliseum Mob (uncredited)
Dave O'Brien
Christian on Stairway (uncredited)
Sally Rand
Crocodiles' Victim (uncredited)
Arthur Shields
Chaplain Costello (1944 Re-Release Prologue) (uncredited)
Tom Tully
Hoboken (1944 Re-Release Prologue) (uncredited)