- Optician
- Outlet store
- Optical wholesaler
- Observation deck
- Oil store
- Orthodontist
- Otolaryngologist
- Ophthalmology clinic
- Otolaryngology clinic
- Occupational health service
- Occupational medical physician
- Outdoor swimming pool
- Office equipment rental service
- Oil field equipment supplier
- Orthopedic surgeon
- Opel dealer
- Organic drug store
- Oriental rug store
- Off roading area
- Office space rental agency