Malcolm McDowell
Caligula
Teresa Ann Savoy
Drusilla
Helen Mirren
Caesonia
Peter O'Toole
Tiberius
John Steiner
Longinus
G
Guido Mannari
Macro
Paolo Bonacelli
Chaerea
Leopoldo Trieste
Charicles
Giancarlo Badessi
Claudius
Mirella D'Angelo
Livia
Anneka Di Lorenzo
Messalina
Lori Wagner
Agrippina
Adriana Asti
Ennia
John Gielgud
Nerva
B
Bruno Brive
Gemellus
R
Rick Parets
Mnester
P
Paula Mitchell
Subura Singer
Osiride Pevarello
Giant
Donato Placido
Proculus
Angela La Vorgna
Tortured Slave (uncredited)
John Stacy
Senator Acesio