- Onion News Empire (2013)
- Oniroku Dan: Bikyoshi jigokuzeme (Beautiful Teacher in Torture Hell) (1985)
- Online (2013)
- Only Angels Have Wings (1939)
- Only God Forgives (2013)
- Only Humans (2018)
- Only Lovers Left Alive (2013)
- Only Mine (2019)
- Only The Brave (2006)
- Only the Dead (2015)
- Only the Valiant (1951)
- Only the Young (2012)
- Only Yesterday (1991)
- Only Yesterday: The Carpenters' Story (2007)
- Only You (1992)
- Onna ga kaidan wo agaru toki (When a Woman Ascends the Stairs) (1960)
- Onna Hissatsu Ken (Sister Street Fighter) (1974)