- Richard Harrison
- Glaucus
- Marilù Tolo
- Ena
- Philippe Hersent
- Claudius
- Livio Lorenzon
- Prefect of the court
- Gianni Solaro
- Cassius Chaerea
- Giuseppe Addobbati
- Lucilius
- Maria Laura Rocca
- Procusa
- Lucia Bomez
- Ena's Friend
- Charles Borromel
- Caligola
- Lisa Gastoni
- Messalina
- Jean Claudio
- Gaio Silio
- Arnaldo Dell'Acqua
- Member of Lucilius' escort
- Fortunato Arena
- Bearded Soldier / Attacker (uncredited)
- Bruno Ariè
- Fighting Soldier
- Ugo Attanasio
- Pontifex Maximus
- Silvana Bacci
- Messalina's Maiden
- Angelo Boscariol
- Roman Barker
- Augusto Brenna
- Consul
- Aldo Canti
- Fighter with Glaucus
- Angelo Casadei
- Servant
- Amerigo Castrighella
- Gladiator
- Domenico Cianfriglia
- Hitman
- Arnaldo Fabrizio
- Caligola's Dwarf
- Jimmy il Fenomeno
- Blond Briton with tresses
- Gilberto Galimberti
- Soldier Holding Glaucus
- Alfonso Giganti
- Roman
- Mauro Mannatrizio
- Soldier
- Giuseppe Marrocco
- Spectator
- Giuseppe Mattei
- Gladiator Trainer
- Emilio Messina
- Gladiator
- Roberto Messina
- Guard at Arena
- Sandro Mondini
- Party Guest
- Paul Naschy
- Extra
- Piero Pastore
- British Ambassador
- Nello Pazzafini
- Member of Lucilius' Escort
- Clemente Ukmar
- Soldier
- Franco Ukmar
- Hitman / Soldier (uncredited)
- Sergio Ukmar
- Soldier
- Rinaldo Zamperla
- Hitman
