- Office accessories wholesaler
- Orchid farm
- Oxygen cocktail spot
- Offal pot cooking restaurant
- Oldsmobile dealer
- Office refurbishment service
- Oriental goods store
- Oriental medicine clinic
- Orchid grower
- Outdoor equestrian facility
- Oyster supplier
- Okonomiyaki restaurant
- Organ donation and tissue bank
- Oriental medical clinic
- Office of Vital Records