- Outboard motor store
- Outdoor activity organiser
- Optometrist
- Outerwear store
- Occupational health service
- Observation deck
- Open air museum
- Olive oil manufacturer
- Oriental rug store
- Oil and gas exploration service
- Olive oil bottling company
- Olive oil cooperative
- Oil refinery
- Oil store
- Office
- Organic restaurant
- Oil change service
- Outdoor bath
- Observatory
- Otolaryngology clinic