Companies catalogue
- O'BRIENS BAR & GRILL, Cambridge
- OAC Centennial Arboretum Centre, Guelph
- OATC, Tillsonburg
- ODAS Park - Orillia and District Agricultural Society, Severn
- OLG Casino Brantford, Brantford
- OLG Slots at Flamboro Downs, Hamilton
- OMTC Tennis Club, Shanty Bay
- ONE Movement, Cambridge
- OPP Museum, Orillia
- OPTIKLAB Microfabrication Inc., Hamilton
- OPULENCE Wedding Design, Thornton
- OSTTC - Ogwehoweh Skills and Trades Training Centre, Ohsweken
- Oak Hall, Hamilton
- Oakhill Cemetery, Brantford
- Oakview Terrace Reception Centre, Richmond Hill
- Oasis Hall, Cambridge
- Ohsweken Baptist Church, Ohsweken
- Ohsweken Speedway, Ohsweken
- Oil Tech, Barrie
- Ojibway Storyteller, Brantford
- Old Town Hall Association, Waterford
- Old Town Hall Auctions, Brant
- Oliver Chimney Sweeps, Milton
- Olympia Court Apartments, Cambridge
- On Side Restoration Services, Woodstock
- On The Level Home Inspections, Brantford
- On The Wall Taxidermy, Uxbridge
- On the Lam, Brantford
- Onbelay Capital Inc, Cambridge
- Oneida Business Park, Caledonia
- Onondaga Community Hall, Brantford
- Ontario Addiction Treatment Centre, Kitchener
- Ontario Addiction Treatment Centres, Cambridge
- Ontario Agriculture/Food Dept, Brantford
- Ontario Broiler Hatching Egg & Chick Commission, Guelph
- Ontario Clean Water Agency, Coldwater
- Ontario Clean Water Agency, Wasaga Beach
- Ontario Conservatory Of Music, Hamilton
- Ontario Conservatory Of Music, Kitchener
- Ontario Conservatory of Music, Brantford
- Ontario Court of Justice, Kitchener
- Ontario Court of Justice, Burlington
- Ontario Cycling Association, Milton
- Ontario Diagnostic Cardiology Inc, Cambridge
- Ontario Disability Support Program, Brantford
- Ontario Driver Examination Ofc, Brantford
- Ontario Duct Cleaning, Breslau
- Ontario Enforcement & Vehicle, Brantford
- Ontario Enforcement Office, Brantford
- Ontario First Nations Economic Developers Association, Brantford
- Ontario Funeral Celebrants, Hamilton
- Ontario Ginseng Growers Assn, Simcoe
- Ontario Haflinger Association, Hamilton
- Ontario Housing Ministry, Cambridge
- Ontario Housing Ministry, Kitchener
- Ontario Licences-Driver, Brantford
- Ontario Livestock Exchange Inc, Waterloo
- Ontario March of Dimes, Brantford
- Ontario March of Dimes, Brantford
- Ontario Members of Parliament, Brantford
- Ontario Ministry of Aboriginal, Brantford
- Ontario Nurses' Assn, Hamilton
- Ontario Osteopathic Association, Hamilton
- Ontario Plowmen's Association, Guelph
- Ontario Provincial Police, Brant
- Ontario Provincial Police (Opp), Burford
- Ontario Sailing, Hamilton
- Ontario Sheriff Dept, Brantford
- Ontario Small Claims Court, Kitchener
- Ontario Snowcruises, Minesing
- Ontario Standard Bred Adoption Society, Milton
- Ontario Waste Water Treatment, Shanty Bay
- Ontario Works Brant - Social Services, Brantford
- Ontario Works Mountain Office, Hamilton
- Ontario Yachts Ltd, Burlington
- Ontario's Lake Country - Orillia & area's four season playground!, Orillia
- Opal Baths & Design, Burlington
- Open Windows 2 Wellness, Brantford
- Open Windows 2 Wellness, Brantford
- Open Windows 2 Wellness, Allergy, Acupuncture & Anti-Aging Clinic, Brantford
- Oriental Restaurant, Brantford
- Original Traders Energy, Caledonia
- Orillia Youth Centre, Orillia
- Oro Beach Ontario, Oro Station
- Oro Medonte Landfill, Oro Station
- Orsan Air Services, Kitchener
- OrvAuto Accessories & Signs, Barrie
- OshKosh B'gosh, Newmarket
- Osler Court Apartments, Hamilton
- Osler House, Hamilton
- Osler House Bed and Breakfast, Hamilton
- Our Lady of Fatima Roman Catholic Church, Cambridge
- Our Lady of Mount Carmel Academy, New Hamburg
- Our Lady of Providence Catholic Elementary School, Brantford
- Ovation Hall Training Centre, Newmarket
- Oxford Community Child Care Inc., Woodstock
- Oxford Condominium Corporation No 15, Tillsonburg
- Oxford Energy Solutions Inc, Woodstock
- Oxford Fish & Game Club, Woodstock
- Oxford Learning Newmarket, Newmarket