Companies catalogue
- O'Brien King Consultants, Toronto
- O'Connor Public School, Toronto
- O'Donnell, Robertson & Partners, Toronto
- O.H. Multimedia, Ohsweken
- OAHAS - The Ontario Aboriginal AIDS/HIV Strategy, Toronto
- OBQ Burgers, Toronto
- OCADU Graduate Programs, Toronto
- OLEKT Inc., Toronto
- OM MacKillop Public School, Richmond Hill
- OMSSA, Toronto
- ONGO Immigration Consulting, Toronto
- OPA! of Greece Dundas Street, Toronto
- ORG&HPS, Toronto
- Oak Ridge Trail, Richmond Hill
- Oakdale Park Middle School, Toronto
- Oakridge Junior Public School, Toronto
- Oakville Naturopathic Clinic, Oakville
- Oakville Sight & Sound, Oakville
- Oakwest Corporation Limited, Toronto
- Oasis Alternative Secondary School, Toronto
- Occidental Hotels, Toronto
- Ocean Club Waterfront Condominiums, Toronto
- Ocean Grill Restaurant, Toronto
- Octopus Garden Yoga Centre, Toronto
- Odd Job Handyman Services Inc., Toronto
- Odjibik Hair Repair, Toronto
- Odyssey Heights School for Girls, Toronto
- Odyssey Reinsurance Co-Canada, Toronto
- Office of the Commissioner of Housing Equity, Toronto
- Oh My Gyro, Toronto
- Olco Petroleum Group Inc, Pickering
- Old Mill Toronto Event Venue, Toronto
- Older Women's Network, Toronto
- Olympic, Toronto
- Olympic Softee, Toronto
- Olympium Rhythmic Gym Club, Toronto
- Omega Laser Therapy, Mississauga
- Omland Hospitality Products Ltd., Mississauga
- One Bedroom Apartment, Toronto
- One Life Meals, Scarborough
- One Medical Family Practice, Toronto
- One pot （hot pot）take-out, Toronto
- Onkar Foods & Spices, Kitchener
- Onpea, Toronto
- Ontario Assn-Interval Houses, Toronto
- Ontario Black History Society, Toronto
- Ontario Criminal, Toronto
- Ontario Disposal Bins, Toronto
- Ontario Driver & Vehicle Lcnsg, Vaughan
- Ontario Govt Css, Toronto
- Ontario Health & Wellness Centre Inc, Toronto
- Ontario Heritage Centre, Toronto
- Ontario Homeopathy Assn, Toronto
- Ontario Hose Specialties, Mississauga
- Ontario Hostelry Institute, Toronto
- Ontario Investment and Trade Centre, Toronto
- Ontario Ministry of Housing, Toronto
- Ontario Mutual Insurance Association, Cambridge
- Ontario Parole & Probation Office - Riverdale, Toronto
- Ontario Podiatric Medical Assn, Toronto
- Ontario Power Generation Inc, Toronto
- Ontario Power Generation Kipling Site, Toronto
- Ontario Provincial Courts, Toronto
- Ontario Restaurant Hotel & Motel Association, Mississauga
- Ontario Securities Commission- Investor Office, Toronto
- Ontario Sires Stakes, Toronto
- Ontario TCM Centre, Mississauga
- Ontario Transportation Dept, Toronto
- Ontario Weekly Court, Toronto
- Ontario Women's Directorate, Toronto
- Optimum Care Inc, Toronto
- Optimum Talent, Toronto
- Optimum Talent Markham, Markham
- Options For Homes, Toronto
- Opus Canada Holdings Corporation, Mississauga
- Opus Employment, Vaughan
- Opus Hair, Richmond Hill
- Orde Street Junior Public School, Toronto
- Ordower Law Professional Corporation, Toronto
- Orefinders, Toronto
- Organic Beaute Collections Inc., Mississauga
- Original Grill, Toronto
- Oriole Park Junior Public School, Toronto
- Orley Grill, Richmond Hill
- Ormston List Frawley LLP, Toronto
- Orvana Minerals Corporation, Toronto
- Osmow's, Vaughan
- Osmow's, Toronto
- Osmow's Grill Downtown, Toronto
- Osmow's Streetsville, Mississauga
- Ossington Developments, Toronto
- Osteopathic Manuel, Vaughan
- Our Lady of Good Voyage, Mississauga
- Out of the Cold, Toronto
- Ouzeri, Toronto
- Ovation At City Ctr, Mississauga
- Owen Public School, Toronto
- Owenwood Public School, Mississauga
- Own Housing Co-Op, Toronto
- Ozzy's Burgers, Toronto