Companies catalogue
- O'Neill Dental Hygiene Clinic, Ayr
- O'Neill Denture Clinic, Ayr
- ONE Fertility, Burlington
- OPIRG McMaster, Hamilton
- Oak Gables Golf Club, Hamilton
- Oil Country Truck Shop, Edmonton
- Old Orchard Farm, Milton
- Old Town Hall, Hamilton
- Oliver M Smith Kawenniio, Ohsweken
- Omar Castellanos ( ACN Rep.), Brantford
- Omega Family Restaurant, Kitchener
- One Fertility Kitchener, Kitchener
- Ontario Alliance of Christian Schools, Hamilton
- Ontario Correctional Services College, Hamilton
- Ontario Disability Support Program, Burlington
- Ontario Dock Works, Innerkip
- Ontario Driver Examination, Brantford
- Ontario Fire Truck Inc, Hamilton
- Ontario Ministry of Housing, Hamilton
- Ontario Ministry-Finance, Hamilton
- Ontario Trillium Foundation-Brant Haldimand Norfolk office, Brantford
- Ontario Truck Driving School, Brantford
- Ontario Truck Driving School, Kitchener
- Ontario Truck Driving School OTDS, Hamilton
- Ontario Waste, Burlington
- Onyx Urgent Care, Kitchener
- Opta Minerals Inc., Hamilton
- Optical in Zehrs, Cambridge
- Optical in Zehrs, Cambridge
- Orchard Home Farm, Saint George
- Order Sons of Italy, Hamilton
- Original Barbershop, Edmonton
- Osteoporosis Diagnostic Services (Brantford), Brantford
- Out-Back Restaurant & Lounge, Woodstock
- Owen Anderson-Magician, Hamilton
- Oxford County, Woodstock
- Oxford County, Woodstock
- Oxford County Administration Building, Woodstock
- Oxford County Housing Corporation, Woodstock
- Oxford County Patrol Garages, Drumbo
- Oxford County Waste Management Facility (landfill), Salford
- Oxford County Woodingford, Woodstock
- Oxford Cruise Intl, Norwich
- Oxford Learning Ancaster, Hamilton
- Oxford Learning Cambridge, Cambridge
- Oxford Learning Hamilton, Hamilton
- Oxford Learning Kitchener South, Kitchener
- Oxford Learning Paris, Brant
- Oxford Trophies, Mount Elgin