Marlon Brando

Mark Antony

James Mason

Brutus

John Gielgud

Cassius

Louis Calhern

Julius Caesar

Edmond O'Brien

Casca

Greer Garson

Calpurnia

Deborah Kerr

Portia

George Macready

Marullus

Michael Pate

Flavius

Richard Hale

A Soothsayer

Alan Napier

Cicero

John Hoyt

Decius Brutus

Tom Powers

Metellus Cimber

William Cottrell

Cinna

Jack Raine

Trebonius

Ian Wolfe

Ligarius

Morgan Farley

Artemidorus

Bill Phipps

Servant to Antony

Douglass Watson

Octavius Caesar

Douglass Dumbrille

Lepidus

Michael Ansara

Pindarus

Dayton Lummis

Messala

Edmund Purdom

Strato

Paul Guilfoyle

First Citizen of Rome

John Doucette

A Carpenter, Second Citizen

Lawrence Dobkin

Third Citizen of Rome

Jo Gilbert

Fourth Citizen of Rome

John Hardy

Lucius

Chester Stratton

Servant to Caesar

Lumsden Hare

Publius

Vic Perry

Popilius Lena

Michael Tolan

Officer to Octavius

Rhys Williams

Lucilius

John Lupton

Varro

John Parrish

Titinius

Joe Waring

Clitus

Stephen Roberts

Dardanius

Thomas Browne Henry

Volumnius

David Bond

Citizen of Rome

Ann Tyrrell

Citizen of Rome

John O'Malley

Citizen of Rome

Oliver Blake

Citizen of Rome

Alvin Hurwitz

Citizen of Rome

Donald Elson

Citizen of Rome

John Call

Citizen of Rome

Rudy Germane

Citizen of Rome (uncredited)