Marlon Brando as Mark Antony

James Mason as Brutus

John Gielgud as Cassius

Louis Calhern as Julius Caesar

Edmond O'Brien as Casca

Greer Garson as Calpurnia

Deborah Kerr as Portia

George Macready as Marullus

Michael Pate as Flavius

Richard Hale as A Soothsayer

Alan Napier as Cicero

John Hoyt as Decius Brutus

Tom Powers as Metellus Cimber

William Cottrell as Cinna

Jack Raine as Trebonius

Ian Wolfe as Ligarius

Morgan Farley as Artemidorus

Bill Phipps as Servant to Antony

Douglass Watson as Octavius Caesar

Douglass Dumbrille as Lepidus

Michael Ansara as Pindarus

Dayton Lummis as Messala

Edmund Purdom as Strato

Paul Guilfoyle as First Citizen of Rome

John Doucette as A Carpenter, Second Citizen

Lawrence Dobkin as Third Citizen of Rome

Jo Gilbert as Fourth Citizen of Rome

John Hardy as Lucius

Chester Stratton as Servant to Caesar

Lumsden Hare as Publius

Vic Perry as Popilius Lena

Michael Tolan as Officer to Octavius

Rhys Williams as Lucilius

John Lupton as Varro

John Parrish as Titinius

Joe Waring as Clitus

Stephen Roberts as Dardanius

Thomas Browne Henry as Volumnius

David Bond as Citizen of Rome

Ann Tyrrell as Citizen of Rome

John O'Malley as Citizen of Rome

Oliver Blake as Citizen of Rome

Alvin Hurwitz as Citizen of Rome

Donald Elson as Citizen of Rome

John Call as Citizen of Rome

Rudy Germane as Citizen of Rome (uncredited)