- Robert Taylor
- Marcus Vinicius
- Deborah Kerr
- Lygia
- Leo Genn
- Petronius
- Peter Ustinov
- Nero
- Patricia Laffan
- Poppaea
- Finlay Currie
- Peter
- Abraham Sofaer
- Paul
- Marina Berti
- Eunice
- Buddy Baer
- Ursus
- Felix Aylmer
- Plautius
- Nora Swinburne
- Pomponia
- Ralph Truman
- Tigellinus
- Norman Wooland
- Nerva
- Peter Miles
- Nazarius
- Geoffrey Dunn
- Terpnos
- Nicholas Hannen
- Seneca
- D.A. Clarke-Smith
- Phaon
- Rosalie Crutchley
- Acte
- John Ruddock
- Chilo
- Arthur Walge
- Croton
- Elspeth March
- Miriam
- Strelsa Brown
- Rufia
- Alfredo Varelli
- Lucan
- Roberto Ottaviano
- Flavius
- William Tubbs
- Anaxander
- Pietro Tordi
- Galba
- Marika Aba
- Assyrian Dancer at Nero's Banquet
- Adriano Ambrogi
- Wine Bibber
- Anna Arena
- Undetermined Role
- Alfred Baillou
- Christian Prisoner in Arena
- Giacomo Barnas
- Senator
- Scott R. Beal
- Fisherman
- John Binns
- Officer
- Francesca Biondi
- Slave Girl
- Alice Bishop
- Serving Woman
- Carlo Borelli
- Noble
- Leslie Bradley
- Hasta
- Alfred Brown
- Undetermined Role
- Phyllis Brown
- Undetermined Role
- Valentino Bruchi
- Mirmillon
- Rosemary Burt
- Banquet Lady
- Dante Ciriaci
- Wine Bibber
- Frank Colson
- Undetermined Role
- Adrienne Corri
- Young Christian Girl
- Luca Cortese
- Old Man
- David Craig
- Little Boy
- Maurice De Bosardi
- Undetermined Role
- Daniel De Jonghe
- Apostle
- Michael De Krasny
- Banquet Man
- Liana Del Balzo
- Undetermined Role
- Jack Del Rio
- Apostle
- Lia Di Leo
- Pedicurist
- Eduardo Di Persis
- Undetermined Role
- Mildred Dudzik
- Girl
- Gabriella Fabrizio
- Child
- Franco Fantasia
- Undetermined Role
- Cesare Fasulo
- Noble
- Al Ferguson
- Apostle
- Enzo Fiermonte
- Mounted Captain
- Enrico Formichi
- Man with Wine Cup
- John Fostini
- Young Unbaptized Man
- Lydia Fostini
- Undetermined Role
- Dino Galvani
- Senator
- Richard Garrick
- Slave
- Gianni Gazzoti
- Lydia Guard
- Jack George
- Fisherman
- Carlo Ghisini
- Guard
- Trudy Glassford
- Undetermined Role
- Joan Griffiths
- Undetermined Role
- Evelyn Guignard
- Girl
- Robin Hughes
- Christ
- Adam Jennette
- Undetermined Role
- Philip Kieffer
- Apostle
- Gipsy Kiss
- Slave Girl
- Lee Kresel
- Undetermined Role
- Richard Larke
- Guard
- Sophia Loren
- Lygia's Slave
- Giovanni Lovatelli
- Banquet Man
- Helena Makowska
- Older Woman
- Anna Mancini
- Nubian Slave Girl
- Michael Mark
- Fisherman
- Clelia Matania
- Parmenida
- Richard McNamara
- Legionnaire
- Harriet Medin
- Undetermined Role
- Dario Michaelis
- Lydia Guard
- Ernesto Molinari
- Fisherman
- John Myhers
- Guard
- Vincent Neptune
- Apostle
- Attillio Olivo
- Servant
- Riette Osborne
- Banquet Lady
- Anna Maria Padoan
- Young Unbaptized Woman
- Riccardo Pantellini
- Guard
- Louis Payne
- Apostle
- Walter Pidgeon
- Narrator
- Aldo Pini
- Headkeeper
- Alberto Plebani
- Steward
- Michael Proben
- Undetermined Role
- Paola Quattrini
- Crying Girl
- Dino Raffaelli
- Undetermined Role
- George Restivo
- Apostle
- Kenneth Richards
- Guard
- Alfredo Rizzo
- Hairdresser
- Giuseppe Rodi
- Schipio
- Amerigo Santarelli
- Guard Tying the Christians
- Leonardo Scavino
- Undetermined Role
- Joseph Sebaroli
- Marcus Guard
- Alessandro Serbaroli
- Officer
- Jurek Shabelewski
- Faun
- John Sleeter
- Undetermined Role
- Lujo Sostarich
- Charon
- Armando Spaccarelli
- Guard
- Bud Spencer
- Imperial Guard
- Jane Sprague
- Banquet Lady
- Raffaele Tana
- Undetermined Role
- Elizabeth Taylor
- Christian Prisoner in Arena
- William Taylor
- Guard Captain / Marcus Guard (uncredited)
- Michael Tor
- Centurian
- Giuseppe Tosi
- Wrestler
- Carlo Tricoli
- Apostle
- Renato Valente
- Guard
- Scilla Vannucci
- White Slave Girl
- Giuseppe Varni
- Hairdresser
- Dianora Veiga
- Slave Girl
- Harry J. Vejar
- Fisherman
- Romilda Villani
- Slave Girl
- Benjamin Wilkes
- Undetermined Role
- Maria Zanoli
- Undetermined Role
