- Oncologist
- Opera house
- Oxygen equipment supplier
- Ophthalmologist
- Orthotics & prosthetics service
- Office accessories wholesaler
- Office equipment repair service
- Orphanage
- Olive oil manufacturer
- Oyster supplier
- Olive oil cooperative
- Oriental goods store
- Optical products manufacturer
- Oriental medical clinic
- Off-road race track
- Orchid farm
- Office
- Office services
- Outdoor bath
- Office supply