- Osteopath
- Outdoor sports store
- Ophthalmologist
- Oriental rug store
- Opera house
- Oil and gas exploration service
- Olive oil bottling company
- Oil wholesaler
- Olive oil cooperative
- Outboard motor store
- Occupational therapist
- Organic restaurant
- Orphanage
- Office accessories wholesaler
- Oral and maxillofacial surgeon
- Oriental medicine clinic
- Oxygen equipment supplier
- Otolaryngology clinic
- Outdoor equestrian facility
- Optical products manufacturer