| Person | Type | Job | Role(s) |
|---|---|---|---|
 Alex North | Crew | Sound | Original Music Composer |
 Amato Garbini | Crew | Costume & Make-Up | Makeup Artist |
Edward C. Carfagno | Crew | Art | Art Direction |
Ernest Day | Crew | Camera | Camera Operator |
Ernest Walter | Crew | Editing | Editor |
 Erwin Hillier | Crew | Camera | Director of Photography |
Franklin Milton | Crew | Sound | Sound Recordist |
 George Englund | Crew | Production | Producer |
George W. Davis | Crew | Art | Art Direction |
Giancarlo Del Brocco | Crew | Costume & Make-Up | Key Makeup Artist |
Hugh Hunt | Crew | Art | Set Decoration |
James Kennaway | Crew | Writing | Screenplay |
John Patrick | Crew | Writing | Screenplay |
 Michael Anderson | Crew | Directing | Director |
Morris L. West | Crew | Writing | Novel |
Orietta Nasalli Rocca | Crew | Costume & Make-Up | Costume Design |
Tony Brandt | Crew | Directing | Assistant Director |
Kurt Doubrowsky | Crew | Sound | Sound Mixer |
 Anthony Quinn | Cast | Actor | Kiril Lakota |
 Arnoldo Foà | Cast | Actor | Gelasio (as Arnoldo Foa') |
 Arthur Howard | Cast | Actor | English Cardinal |
 Barbara Jefford | Cast | Actress | Dr. Ruth Faber |
 Burt Kwouk | Cast | Actor | Chairman Peng |
 Clive Revill | Cast | Actor | Tovarich Vucovich |
 David Janssen | Cast | Actor | George Faber |
 Frank Finlay | Cast | Actor | Igor Bounin |
 George Pravda | Cast | Actor | Gorshenin (credit only) |
 Gerald Harper | Cast | Actor | Brian |
 Isa Miranda | Cast | Actress | The Marchesa |
 Jean Rougeul | Cast | Actor | Dominican |
 John Frederick | Cast | Actor | American Cardinal (uncredited) |
 John Gielgud | Cast | Actor | The Elder pope |
 Laurence Olivier | Cast | Actor | Piotr Ilyich Kamenev |
 Leo McKern | Cast | Actor | Cardinal Leone |
 Leopoldo Trieste | Cast | Actor | Dying Man's Friend |
Lex Monson | Cast | Third African Priest (uncredited) | |
 Marne Maitland | Cast | Actor | Cardinal Rahamani |
 Niall MacGinnis | Cast | Actor | Capuchin Monk |
 Oskar Werner | Cast | Actor | Fr. David Telemond |
 Paul Rogers | Cast | Actor | Augustinian |
 Peter Copley | Cast | Actor | English Cardinal |
 Rosemary Dexter | Cast | Actress | Chiara |
 Vittorio De Sica | Cast | Actor | Cardinal Rinaldi |
 Arnaldo Caivano | Cast | Dying Man (uncredited) | |
Inna Alexeievna | Cast | Party Guest (uncredited) | |
| Person | Type | Job | Role(s) |
