 | Le Mystère Bardot (2012) |
 | Back When We Were Grownups (2004) as Paul 'Poppy' Davitch |
 | Living with the Dead (2002) as Allan Van Praagh |
 | Prancer Returns (2001) |
 | The Omen Legacy (2001) as Narrator (voice) |
 | Sarah, Plain and Tall: Winter's End (1999) as John Witting |
 | Joe D'Amato Totally Uncut - The Erotic Experience (1999) as (archive footage) |
 | Treasure Island (1999) as Long John Silver |
 | Ebenezer (1998) as Ebenezer Scrooge |
 | The Incredible Adventures of Marco Polo (1998) as Beelzebub |
 | I'll Be Home For Christmas (1997) as Bob Greiser |
 | Monster Mania (1997) as Host |
 | Vem Var Dracula (1996) as Self |
 | Joan Crawford: Always the Star (1996) as Self (archive footage) |
 | Rod Serling: Submitted for Your Approval (1995) as Self |
 | Buffalo Girls (1995) as Bartle Bone |
 | The Swan Princess (1994) as Lord Rothbart (voice) |
 | City Slickers II: The Legend of Curly's Gold (1994) as Duke Page |
 | The Twilight Zone: Rod Serling's Lost Classics (1994) as Dr. Jeremy Wheaton (segment "Where the Dead Are") |
 | Cops & Robbersons (1994) as Jake Stone |
 | Cyborg 2 (1993) as Mercy |
 | Legends of the West (1992) as Host / Self - Judge Roy Bean |
 | Solar Crisis (1992) as Travis |
 | When It Was a Game 2 (1992) as Passage Narrator (voice) |
 | Keep the Change (1992) as Overstreet |
 | Horror of the Hungry Humongous Hungan (1991) as Opening Narration (voice) |
 | City Slickers (1991) as Curly Washburn |
 | Tango & Cash (1989) as Yves Perret |
 | Batman (1989) as Grissom |
 | Outlaw of Gor (1988) as Xeno |
 | Imagine: John Lennon (1988) as Self |
 | Young Guns (1988) as L. G. Murphy |
 | Out of Rosenheim (1987) as Rudi Cox |
 | Gor (1987) as Xenos |
 | Night of 100 Stars II (1985) as Self |
 | Hollywood Out-takes and Rare Footage (1983) as Self (archive footage) (uncredited) |
 | Alone in the Dark (1982) as Frank Hawkes |
 | Psychic Confession (1982) as Narrator |
 | The Helm of Destiny (1982) as Narration |
 | Evil Stalks This House (1981) as Stokes |
 | Without Warning (1980) as Joe Taylor |
 | Hawk the Slayer (1980) as Voltan |
 | The Golden Moment: An Olympic Love Story (1980) as Whitey Robinson |
 | The Ivory Ape (1980) as Marc Kazarian |
 | The Last Ride of the Dalton Gang (1979) as Will Smith |
 | Cocaine Cowboys (1979) as Raphael |
 | Buck Rogers in the 25th Century: Planet of the Slave Girls (1979) as Kaleel |
 | Portrait of a Hitman (1979) as Jim Buck |
 | The Shape of Things to Come (1979) as Omus |
 | Angels' Brigade (1979) as Mike Farrell |
 | The One Man Jury (1978) as Lieutenant Wade |
 | Unknown Powers (1978) as Himself - Host |
 | National Geographic: The Volga (1977) as Narrator (voice) |
 | Welcome to Blood City (1977) as Frendlander |
 | Kolossal - I magnifici Macisti (1977) |
 | The Unknown Force (1977) as Self - Host |
 | Sangue di sbirro (1976) as Duke |
 | I padroni della città (1976) as Scarface' Manzari |
 | Eva nera (1976) as Judas Carmichael |
 | Squadra antiscippo (1976) as Norman Shelley / Richard J. Russo |
 | Diamante Lobo (1976) as Sam Clayton |
 | Safari Express (1976) as van Daalen |
 | L'infermiera (1975) as Mr. Kitch |
 | Rickles (1975) |
 | Africa Express (1975) as Robert Preston / Willaim Hunter |
 | The Four Deuces (1975) as Vic Morono, the Boss |
 | Il richiamo del lupo (1975) as William Bates |
 | The Hatfields and the McCoys (1975) as Devil Anse Hatfield |
 | The Godchild (1974) as Rourke |
 | Dracula (1974) as Dracula |
 | Craze (1974) as Neal Mottram |
 | Oklahoma Crude (1973) as Hellman |
 | Blu Gang e vissero per sempre felici e ammazzati (1973) as Hillman |
 | Imagine (1972) as Self |
 | Tedeum (1972) as Buck Santini |
 | Chato's Land (1972) as Quincey Whitmore |
 | Si può fare… amigo (1972) as Sonny Bronston |
 | The Horsemen (1971) as Tursen |
 | Vamos a matar, compañeros (1970) as John |
 | Monte Walsh (1970) as Chet Rollins |
 | The McMasters (1970) as Kolby |
 | La legione dei dannati (1969) as Charley MacPherson |
 | Che! (1969) as Fidel Castro |
 | Marquis de Sade: Justine (1969) as Antonin |
 | Hora cero: Operación Rommel (1969) as Major John Heston |
 | The Desperados (1969) as Parson Josiah Galt |
 | Il mercenario (1968) as Ricciolo ("Curly") |
 | Un dollaro per 7 vigliacchi (1968) as Matteo Cirini (voice) (uncredited) |
 | Las Vegas: 500 millones (1968) as Douglas |
 | The Strange Case of Dr. Jekyll and Mr. Hyde (1968) as Dr. Jekyll / Mr.Hyde |
 | Kill a Dragon (1967) as Rick Masters |
 | Torture Garden (1967) as Ronald Wyatt (segment 4 "The Man Who Collected Poe") |
 | Cinéastes de notre temps : Le Dinosaure et le Bébé, dialogue en huit parties entre Fritz Lang et Jean-Luc Godard (1967) as Jeremy Prokosch (archive footage) |
 | The Spy in the Green Hat (1967) as Louis Strago |
 | And Still Champion! The Story of Archie Moore (1967) as Narrator (voice) |
 | Alice Through the Looking Glass (1966) as Jabberwock |
 | The Professionals (1966) as Jesus Raza |
 | Once a Thief (1965) as Walter Pedak |
 | Paparazzi (1964) as Self |
 | Le Parti des choses : Bardot et Godard (1964) as Self |
 | Le Mépris (1963) as Jeremy Prokosch |
 | La guerra continua (1962) as Jack |
 | Il Criminale (1962) as Herr Bauer / Schneider |
 | Barabbas (1961) as Torvald |
 | Il giudizio universale (1961) as Matteoni |
 | I mongoli (1961) as Ogataï |
 | Rosmunda e Alboino (1961) as Alboino |
 | The Barbarians (1960) as Revak |
 | Austerlitz (1960) as Gen. Weirother |
 | Flor de mayo (1959) as Jim Gatsby |
 | Ten Seconds to Hell (1959) as Eric Koertner |
 | The Man Inside (1958) as Milo March |
 | The Death of Manolete (1957) as Manolete |
 | House of Numbers (1957) as Arnie Judlow / Bill Judlow |
 | The Lonely Man (1957) as Jacob Wade |
 | The Last Tycoon (1957) as Monroe Stahr |
 | Requiem for a Heavyweight (1956) as Harlan 'Mountain' McClintock |
 | Attack (1956) as Joe Costa |
 | I Died a Thousand Times (1955) as Roy Earle / Roy Collins |
 | The Big Knife (1955) as Charles Castle |
 | Kiss of Fire (1955) as El Tigre |
 | The Silver Chalice (1954) as Simon The Magician |
 | Sign of the Pagan (1954) as Attila |
 | Man in the Attic (1953) as Slade |
 | Flight to Tangier (1953) as Gil Walker |
 | Arrowhead (1953) as Toriano |
 | Second Chance (1953) as Cappy Gordon |
 | Shane (1953) as Jack Wilson |
 | Sudden Fear (1952) as Lester Blaine |
 | Halls of Montezuma (1951) as Pigeon Lane |
 | Panic in the Streets (1950) as Blackie |
| | New Line: Independent Legacies as Self (archive footage) |
| | Legends of the West Executive Producer |
