 | Richard Burton als Father Philip Lamont |
 | Linda Blair als Regan MacNeil |
 | Louise Fletcher als Dr. Gene Tuskin |
 | Max von Sydow als Father Lankester Merrin |
 | Kitty Winn als Sharon Spencer |
 | Paul Henreid als The Cardinal |
 | James Earl Jones als Older Kokumo |
 | Ned Beatty als Edwards |
 | Belinda Beatty als Liz |
 | Rose Portillo als Spanish Girl |
| Barbara Cason als Mrs. Phalor |
| Tiffany Kinney als Deaf Girl |
| Joey Green als Young Kokumo |
| Fiseha Dimetros als Young Monk |
 | Ken Renard als Abbot |
 | Hank Garrett als Conductor |
| Lorry Goldman als Accident Victim |
| Bill Grant als Taxi Driver |
| Shane Butterworth als Gary Tuskin |
| Joely Adams als Linda Tuskin |
| Robert Lussier |
| Charles Parks |
 | Richard Paul als Man on the Plane |
| George Skaff |
 | Marianne Muellerleile als Patient (uncredited) |
 | Dana Plato als Sandra Phalor (uncredited) |
| Kelley Karel als Singer (uncredited) |
| Karen Knapp als Pazuzu (uncredited) |
| John Boorman | Producer |
| Ennio Morricone | Original Music Composer |
| John Boorman | Director |
| Richard Macdonald | Production Design |
| Tom Priestley | Editor |
| William Goodhart | Writer |
| Richard Lederer | Producer |
| William A. Fraker | Director of Photography |
| Dan Perri | Title Designer |
| Rospo Pallenberg | Writer |
| Whitey Hughes | Stunt Coordinator |
| Jack T. Collis | Art Direction |
| John P. Austin | Set Decoration |
| Robert De Mora | Costume Design |
| Ron Spang | Assistant Editor |
| Axel Hubert Sr. | Associate Editor |
| John Merritt | Editor |
| Charles Orme | Associate Producer |
| William Peter Blatty | Characters |
| Ron Berkeley | Makeup Artist |
| Wayne Edgar | Makeup Artist |
| Gary Liddiard | Makeup Supervisor |
| Lynda Gurasich | Hair Supervisor |
| Carrie White | Additional Hairstylist |
| Gae Clark Butler | Hairdresser |
| Terry Miles | Makeup Artist |
| Dick Smith | Special Effects Makeup Artist |
| John R. Coonan | Unit Production Manager |
| William C. Gerrity | Unit Production Manager |
| Victor Hsu | Second Assistant Director |
| Rospo Pallenberg | Second Unit Director |
| Phil Rawlins | Assistant Director |
| William S. Beasley | Assistant Director Trainee |
| Richard Lawrence | Assistant Art Director |
| Gene Rudolf | Art Direction |
| Richard M. Rubin | Property Master |
| Harold Broner | Construction Coordinator |
| Kathrin Boorman | Draughtsman |
| Jim Atkinson | Sound Effects Editor |
| Les Fresholtz | Sound Re-Recording Mixer |
| Walter Goss | Sound Mixer |
| Michael Minkler | Sound Re-Recording Mixer |
| Arthur Piantadosi | Sound Re-Recording Mixer |
| Russ Hill | Sound Effects Editor |
| Dean Mitzner | Assistant Art Director |
| Peter R. Romero | Assistant Art Director |
| Jim Blount | Special Effects |
| Wayne Edgar | Special Effects |
| Chuck Gaspar | Special Effects |
| Jeff Jarvis | Special Effects |
| Richard Ratliff | Special Effects |
| Albert Whitlock | Visual Effects |
| Roy Kelly | Special Effects |
| Ted Koerner | Special Effects |
| Gerry Johnston | Special Effects Supervisor |
| John Ashby | Stunts |
| May Boss | Stunts |
| Bennie Moore | Stunts |
| Betsy Cox | Costume Supervisor |
| Bruce Walkup | Costume Supervisor |
| Bill Milton | Costumer |
| Eugene Marks | Music Editor |
| Ennio Morricone | Orchestrator |
| Ennio Morricone | Conductor |
| Bonnie Prendergast | Script Supervisor |
