- Optician
- Optometrist
- Orthopedic clinic
- Oil & natural gas company
- Office space rental agency
- Office furniture store
- Organic drug store
- Orthotics & prosthetics service
- Organic farm
- Organic shop
- Off-road race track
- Olive oil bottling company
- Organic food store
- Organic restaurant
- Oriental rug store
- Occupational safety and health
- Outdoor swimming pool
- Occupational therapist
- Occupational health service
- Office equipment supplier