EnglishMalcolm McDowell as Emperor Gaius Germanicus Caesar (Caligula)
Teresa Ann Savoy as Julia Drusilla
Helen Mirren as Caesonia
Peter O'Toole as Emperor Tiberius Caesar
John Steiner as Longinus
Guido Mannari as Macro
Paolo Bonacelli as Chaerea
Leopoldo Trieste as Charicles
Giancarlo Badessi as Claudius
Mirella D'Angelo as Livia
Anneka Di Lorenzo as Messalina
Lori Wagner as Agrippina
Adriana Asti as Ennia
John Gielgud as Nerva
Bruno Brive as Gemellus
Rick Parets as Mnester
Paula Mitchell as Subura Singer
Osiride Peverello as Giant
Donato Placido as Proculus
Patrick Allen as Macro
Eduardo Bergara Leumann as A high priest of Rome
Signe Berger as An Imperial Brothel worker
Eolo Capritti as The executioner
Valerie Rae Clark as Priestes of Isis/Imperial Brothel worker
Jane Hargrave as Priestess of Isis/Imperial Brothel worker
Henrietta Kelogg as An Imperial Brothel worker
John Francis Lane as Guest at Proculus' wedding
Helen Lang as Priestess of Isis/Imperial Brothel worker
Giuseppe Maffioli as Master of Ceremonies
Juliet Morris as An Imperial Brothel worker
Carolyn Patsis as An Imperial Brothel worker
Susanne Saxon as An Imperial Brothel worker
Melanie Sutherland as An Imperial Brothel worker
Bonnie Dee Wilson as An Imperial Brothel worker