- Orthopedic shoe store
- Orthopedic clinic
- Orchestra
- Organic shop
- Oral surgeon
- Occupational medical physician
- Obstetrician-gynecologist
- Organic farm
- Orchard
- Organic restaurant
- Observatory
- Outboard motor store
- Oil change service
- Opel dealer
- Outerwear store
- Occupational health service
- Organic drug store
- Orthotics & prosthetics service
- Observation deck
- Ophthalmologist