The Oasis (aka A Savage Hunter)(1984)

 Oasis of the Zombies(1983)

 Oblivion(1994)

 The Oblong Box(1969)

 The Octagon(1980)

 Octaman(1971)

 Octopus(2000)

 Octopus 2: River of Fear(2002)

 Oddball Hall(1990)

 Odin: Photon Space Sailer Starlight(1986)

 Of Unknown Origin(1983)

 The Offence(1973)

 The Offspring(1986)

 Ol' Dirty Kung Fu (aka Mad, Mad Kung Fu)(1979)

 The Old Dark House(1932)

 Old Mother Riley Meets the Vampire (aka My Son the Vampire & Vampire Over London)(1952)

 Oldboy(2003)

 Ololer Konusmazki (aka The Dead Don't Talk)(1970)

 Omega Cop(1990)

 Omega Doom(1996)

 The Omega Man(1971)

 The Omen(1976)

 On a Dark and Stormy Night(2010)

 On Any Sunday(1971)

 On Deadly Ground(1994)

 On the Beach(1959)

 On the Town(1949)

 Once A Hero(1987)

 Once a Thief(1990)

 Once Upon A Girl(1976)

 Once Upon a Time in China(1991)

 One Body Too Many(1944)

 One Man Jury(1978)

 One Million B.C. (aka Man and His Mate)(1940)

 One Million Years B.C.(1966)

 The One(2001)

 Ong Bak(2003)

 Operation Condor (aka Armor of God 2)(1990)

 Operation Condor 2 (aka Armor of God)(1986)

 Operation Petticoat(1959)

 Operation Pink Squad II(1987)

 Operation White Shark(1966)

 Opstandelsen (aka The Resurrection)(2010)

 Orca(1977)

 The Ordeal (aka Calvaire)(2004)

 Orgazmo(1997)

 Orgy of the Dead(1965)

 Orgy of the Dead (aka La Orgia de Los Muertos)(1972)

 Orgy of the Vampires (aka Vampires' Night Orgy)(1973)

 The Oscar(1966)

 The Other Hell(1980)

 The Other(1972)

 The Others(2001)

 Our Man In Marrakesh(1966)

 Our Winning Season(1978)

 Out of Sync(1995)

 Outland(1981)

 Outlaw Force(1987)

 Outtakes(1987)

 Overdrawn at the Memory Bank(1985)

 Overkill(1996)

 Oversexed Rugsuckers from Mars(1989)