Credits

• 2023 · Leap of Faith: William Friedkin on The Exorcist as Self (archive footage)
• 2011 · Miller's Tale as Self (Archive Footage)
• 2001 · Hellsing as
• 2001 · The Joe Spinell Story as Self
• 1998 · The Eternal as The Doctor
• 1998 · The Fear of God: 25 Years of The Exorcist as Self / Father Karras
• 1996 · Murdered Innocence as Det. Rollins
• 1995 · Mommy as Lt. March
• 1993 · Rudy as Coach Ara Parseghian
• 1992 · Small Kill as Mikie
• 1990 · The Exorcist III as Father Damien Karras / Patient X
• 1987 · Deadly Care as Dr. Miles Keefer
• 1987 · Light of Day as Benjamin Rasnick
• 1984 · A Touch of Scandal as Garrett Locke
• 1984 · Toy Soldiers as Sarge
• 1984 · Terror in the Aisles as Father Karras (archive footage) (uncredited)
• 1982 · Monsignor as Don Vito Appolini
• 1981 · The Best Little Girl in the World as Clay Orlovsky
• 1980 · Marilyn: The Untold Story as Arthur Miller
• 1980 · The Henderson Monster as Dr. Tom Henderson
• 1980 · The Ninth Configuration as Lt. Frankie Reno
• 1979 · Vampire as John Rawlins
• 1978 · The Dain Curse as Owen Fitzstephan
• 1977 · A Dog Called... Vengeance as Aristides Ungria
• 1977 · The Devil's Advocate as Dr. Aldo Meyer
• 1975 · F. Scott Fitzgerald in Hollywood as F. Scott Fitzgerald
• 1975 · A Home of Our Own as Father William Wasson
• 1975 · The Nickel Ride as Cooper
• 1974 · The Horror Hall of Fame: A Monster Salute as Self (archive footage)
• 1973 · The Exorcist as Father Damien Karras