(4.73 out of 5)
- O.S.S. 117 Is Not Dead (1957, France)
- Oasis of the Zombies (1981, France)
- Oblong Box, The (1969, UK)
- Obsessed One, The (1974, Suriname)
- Octagon, The (1980, USA), combo
- Octaman (1971, Mexico / USA)
- October Silk (1980, USA)
- Oddballs (1984, Canada)
- Odds and Evens (1978, Italy)
- Odyssey: The Ultimate Trip (1977, USA)
- Office Girls (1971, Germany)
- Oh! Calcutta! (1972, USA)
- Oh Fanny (1975, USA)
- OK Connery (1967, Italy)
- Oklahoma Woman, The (1956, USA)
- Old Dracula (1974, UK)
- Old Manor of Loose Triangles, The (1984, Poland)
- Old Master, The (1979, Hong Kong)
- Oldest Profession, The (1967, France / Germany / Italy)
- Olga’s Dance Hall Girls (1969, USA)
- Olga’s Girls (1964, USA)
- Olga’s House of Shame (1964, USA)
- Olympic Fever (1979, USA)
- Omega Syndrome (1987, USA)
- On the Reeperbahn at Half Past Midnight (1969, Germany)
- On the Threshold of Space (1956, USA)
- Once Upon a Girl…. (1976, USA)
- Once Upon a Time in China (1991, Hong Kong)
- One Armed Boxer (1971, Taiwan / Hong Kong)
- One Armed Boxer 2 (1975, Taiwan / Hong Kong)
- One Armed Executioner, The (1983, Philippines)
- One-Armed Swordsman, The (1967, Hong Kong)
- One Dark Night (1982, USA)
- One Down, Two to Go (1982, USA)
- One Girl’s Confession (1953, USA)
- One Million Years B.C. (1966, UK)
- One Shocking Moment (1965, USA)
- One Swedish Summer (1968, Sweden / Germany)
- One Thousand Cries Has the Night (1982, USA / Spain)
- One on Top of the Other (1969, Italy / Spain / France)
- One Way at a Time (1979, USA)
- Only a Coffin (1969, Spain / France)
- Open House (1988, USA)
- Open Season (1974, Spain / Switzerland / UK / USA / Argentina)
- Opening of Misty Beethoven, The (1976, USA)
- Opera (1987, Italy)
- Operation 67 (1967, Mexico)
- Operation Apocalypse (1966, Italy / Spain)
- Operation Bikini (1963, USA)
- Operation Conspiracy (1956, UK)
- Operation Delta Force 2: Mayday (1998, USA)
- Operation Fear (1966, Italy), combo, another combo
- Operation Kid Brother (1967, Italy)
- Operation Makonaima (1974, Suriname)
- Operation Pink Squad II (1987, Hong Kong)
- Opposing Force (1986, USA)
- Oracle, The (1985, USA)
- Oregon Passage (1957, USA)
- Orgasmo (1969, Italy / France)
- Orgazmo (1997, USA)
- Orgies of Dr. Orloff, The (1969, Spain / France)
- Orgies of Edo (1969, Japan)
- Orgies of the Gestapo, The (1967, France)
- Orgy of the Dead (1965, USA)
- Orgy of the Dead, The (1973, Spain / Italy)
- Orgy of the Golden Nudes (1964, USA)
- Orgy at Lil’s Place (1963, USA)
- Oriental Vixen (?,?)
- Orientals, The (1962, Italy)
- Orloff and the Invisible Man (1971, France / Spain), combo
- Orphan, The (1979, USA)
- Other Hell, The (1981, Italy)
- Other Side of Julie, The (1978, USA)
- Other, The (1972, USA)
- Our Last Weekend (2011, Spain)
- Our Man in Marrakesh (1966, UK)
- Our Men in Bagdad (1966, Italy / France)
- Out of the Dark (1989, USA)
- Outer Touch (1981, UK)
- Outing, The (1987, USA)
- Outlaw Ladies (1981, USA)
- Outlaw Riders (1971, USA)
- Outlaw Women (1952, USA)
- Over-Exposed (1956, USA)
- Over the Top (1987, USA)
- Overnight Sensations (1977, USA)