OL
- -ol
- 01 (disambiguation)
- 0I (disambiguation)
- 0L (disambiguation)
- Bhumij language
- Guillaume-Antoine Olivier
- HTML element
- Lancaster Royal Grammar School
- O1 (disambiguation)
- OI (disambiguation)
- OL Groupe
- OL Lyonnes
- OL postcode area
- OLT Express Germany
- Offensive lineman
- Office lady
- Ol Chiki script
- Ol Onal
- Old Lace (comics)
- Olympic Games
- Olympique Lillois
- Olympique Lyonnais
- Open Library
- Optics Letters
- Orphaned Land
- Oulu railway station
- Santali language
- Seattle Reign FC
- Singapore-Cambridge GCE Ordinary Level
- St Lawrence College, Ramsgate
- Unified Soil Classification System