Fredric March (Marcus Superbus)
Claudette Colbert (Empress Poppaea)
Elissa Landi (Mercia)
Charles Laughton (Nero)
Ian Keith (Tigellinus)
Ynez Seabury
Nat Pendleton (Strabo)
William V. Mong (Licinius)
James Millican (Capt. Kevin Driscoll (1944 prologue))
Charles B. Middleton (Tyros)
Robert Manning (Philodemus)
Arthur Shields (Chaplain Costello (1944 prologue))
Kent Taylor (A lover)
Tom Tully (Hoboken (1944 prologue))
Florence Turner
Ethel Wales (Complaining wife)
Horace B. Carpenter
Jerome Storm
Stanley Ridges (Chaplian Lloyd (1944 prologue))
Gertrude Norman
Aline MacMahon
Wilfred Lucas
William Forrest (Colonel Hugh Mason (1944 prologue))
Lane Chandler (Christian in chains)
John Carradine (Leader of Gladiators/Christian Martyr/Crowd Voice)
Clarence Burton (Servillius)
Henry Brandon
Joe Bonomo (Mute Giant)
Lionel Belmore (Bettor)
Joel Allen (Bombadier (1944 prologue))
Richard Alexander (Viturius)
Carol Holloway
Dorothy Granger
Harold Healy (Tybul)
Lillian Leighton
Otto Lederer
Angelo Rossitto (Pygmy)
John James (Lieutenant Herb Hanson (1944 prologue))
Ferdinand Gottschalk (Glabrio)
Joyzelle Joyner (Ancaria)
Harry Beresford (Flavius)
Arthur Hohl (Titus)
Tommy Conlon (Stephanus)
Vivian Tobin (Dacia)