Malcolm McDowell
Caligula
Teresa Ann Savoy
Drusilla
Guido Mannari
Macro
John Gielgud
Nerva
Peter O'Toole
Tiberius
Giancarlo Badessi
Claudius
Bruno Brive
Gemellus
Adriana Asti
Ennia
Leopoldo Trieste
Charicles
Paolo Bonacelli
Chaerea
John Steiner
Longinus
Mirella D'Angelo
Livia
Helen Mirren
Caesonia
Rick Parets
Mnester
Paula Mitchell
Subura Singer
Osiride Pevarello
Giant
Donato Placido
Proculus
Anneka Di Lorenzo
Messalina
Maria Mascarielli
Banquet Woman (uncredited)
Donatella Damiani
Breastfeeding nurse (uncredited)
Mario Pascucci
Man at Banquet (uncredited)
Tony Casale
Senator (uncredited)