Sophia Loren as Lucilla

Stephen Boyd as Livius

Alec Guinness as Marcus Aurelius

James Mason as Timonides

Christopher Plummer as Commodus

Anthony Quayle as Verulus

John Ireland as Ballomar

Omar Sharif as Sohamus

Mel Ferrer as Cleander

Eric Porter as Julianus

Finlay Currie as Senator

Andrew Keir as Polybius

Douglas Wilmer as Niger

George Murcell as Victorinus

Norman Wooland as Virgilianus

Michael Gwynn as Cornelius

Virgílio Teixeira as Marcellus

Peter Damon as Claudius

Rafael Luis Calvo as Lentulus

Lena von Martens as Helva

Roland Carey as Barbarian (uncredited)

Margaret Fuller as Part of Court (uncredited)

Mario Ghignone as Gladiators Trainer (uncredited)

Gabriella Licudi as Tauna (uncredited)

Jeffrey O'Kelly as Brother of Livius (uncredited)

Robert Rietti as Opening Narrator (voice / uncredited)

Guy Rolfe as Marius (uncredited)

José Terrón as Soldier on Horse (uncredited)

Friedrich von Ledebur as Barbarian (uncredited)

Patricia Wright as Roman Citizen, Slave Woman (uncredited)