O
O
- Oasis of the Zombies
- Oblivion
- Oblivion 2: Backlash
- The Oblong Box
- Octaman
- Octopus
- Octopus 2: River of Fear
- Oculus
- Oddity
- Of Unknown Origin
- Offerings
- Old
- The Old Dark House (1932)
- The Old Dark House (1963)
- Oldboy (2003)
- Oldboy (2013)
- The Omega Man
- The Omen (1976)
- Damien: Omen II
- Omen III: The Final Conflict
- Omen IV: The Awakening
- The Omen (2006)
- Once Bitten
- Once Upon a Time at Christmas
- 1BR
- One Cut of the Dead
- One Dark Night
- One Hell of a Christmas
- 100 Tears
- One Million AC/DC
- Onibaba
- Open House
- Open Water
- Open Water 2: Adrift
- Open Water 3: Cage Dive
- Open Your Eyes
- Opera
- The Oracle
- Orca
- Orphan
- Orphan: First Kill
- The Orphan
- The Orphanage
- The Other
- The Other Hell
- The Other Side
- The Others
- Otis
- Ouija
- Ouija: Origin of Evil
- Our House
- Out of the Body
- The Outing
- Outpost (2007)
- Outpost: Black Sun
- Outpost: Rise of the Spetsnaz
- Outpost (2022)
- Overlord