- Office
- Opera house
- Orthoptist
- Oil change service
- Outerwear store
- Oil store
- Oil wholesaler
- Orthopedic clinic
- Outlet mall
- Oral and maxillofacial surgeon
- Orthodox church
- Orchard
- Oil field equipment supplier
- Opel dealer
- Otolaryngologist
- Occupational therapist
- Office equipment rental service
- Office supply
- Oil refinery
- Organic drug store