George C. Scott
Lt. William 'Bill' Kinderman
Ed Flanders
Father Joseph Kevin Dyer
Brad Dourif
James Venamun / The Gemini Killer
Jason Miller
Father Damien Karras / Patient X
Nicol Williamson
Father Morning
Lee Richardson
University President
Grand L. Bush
Sergeant Atkins
Tracy Thorne
Nurse Keating
Zohra Lampert
Mary Kinderman
Harry Carey, Jr.
Father Kanavan
Sherrie Wills
Julie Kinderman
James Burgess
Thomas Kintry
John Durkin
Elderly Jesuit
Alexis Chieffet
Counter Attendant
Walt MacPherson
Police Sergeant
David Dwyer
Second Police Officer
William Preston
Old Man in Wheelchair
Demetrios Pappageorge
Casperelii
Nina Hansen
Little Old Lady
Samuel L. Jackson
Dream Blind Man
Shane Wexel
First Dream Boy (uncredited)
Ryan Paul Amick
Second Dream Boy (uncredited)
John Coe
Old Man in Dream (uncredited)
Jodi Long
First Dream Woman (uncredited)
Kathy Gerber
Second Dream Woman (uncredited)
Jan Smook
Radio Man (uncredited)
Amelia Campbell
Young Girl in Dream (uncredited)
C. Everett Koop
Everett Koop
Patrick Ewing
Angel of Death
Clinton Brandhagen
Young Boy in Dream (uncredited)
Michael Criscuolo
Mental Patient (uncredited)
Cindy Cullom
Nurse (uncredited)
Colleen Dewhurst
Satan (voice) (uncredited)
Randy Aaron Fink
Student (uncredited)
Jeff Henry
Angel (uncredited)
Patt Noday
Hospital Ward Priest (uncredited) (unconfirmed)
Manley Pope
Angel (uncredited)
John Thompson
John Thompson - Georgetown Hoyas Basketball Coach (uncredited)
Michael Tove
Man in Purgatory (uncredited)
Brad Waller
Asylum Inmate (uncredited)
Gary Wheeler
Crime Photographer (uncredited)
Teresa Wright
Penitent (uncredited)
Charles Edwin Powell
Patient X Possessed