- Open Water 2: Adrift (2006)
- Open Water 3: Cage Dive (2017)
- Open Windows (2014)
- Opening Night (1977)
- Opera (1987)
- Opera (Terror at the Opera) (1987)
- Operasjon Arktis (2014)
- Operation Amsterdam (1959)
- Operation Avalanche (2016)
- Operation Christmas (2016)
- Operation Chromite (2016)
- Operation Crossbow (1965)
- Operation Cupcake (2012)
- Operation Daybreak (1975)
- Operation Dumbo Drop (1995)
- Operation Endgame (2010)
- Operation Finale (2018)