Companies catalogue
- OK Tire, Edmonton
- OK Tire, Edmonton
- OK Tire, Nisku
- OPSEU Region 2, Welland
- OSSTF Niagara District 22, Thorold
- OZ Tax & Accounting, Edmonton
- Oak Centre, Welland
- Oakwood Park Lodge, Niagara Falls
- Oakwood School Child Care Centre, Port Colborne
- Oban Inn, Niagara-on-the-Lake
- Oddfellows Temple, St. Catharines
- Oh Canada Eh? Dinner Theatre, Niagara Falls
- Oh my Dog Walking, St. Catharines
- Oikonomos Chartered Professional Accountants, Saint Albert
- Oikonomos Chartered Professional Accountants, Saint Albert
- Old Fort Erie, Fort Erie
- Olivia's Pupadise, Niagara Falls
- Olympia Restaurant, Welland
- Omdurman Meat & Grocery, St. Catharines
- Omni Growing Solutions Inc, Niagara-on-the-Lake
- On Command Canada Inc, Niagara Falls
- One Stop Renovations, St. Catharines
- Oneil's Taste Of Jamaica, Niagara Falls
- Ontario Breast Screening Program, Niagara Falls
- Ontario Coroner's Office, St. Catharines
- Ontario Debt Assistance, St. Catharines
- Ontario Disability Support Program, St. Catharines
- Ontario Drivers & Vehicles, Pelham
- Ontario Early Years Centre, Niagara Falls
- Ontario Health Insurance, St. Catharines
- Ontario Land Registry Offices, St. Catharines
- Ontario Natural Resources, Niagara-on-the-Lake
- Ontario Public School, Thorold
- Ontario Street Garage, St. Catharines
- Ontario Supreme-District Court, Welland
- Ontario Truck Driving School, Niagara-on-the-Lake
- Opa & Oma's Diner, St. Catharines
- Opal Dental Lab Inc., Niagara Falls
- Opal PDA Inc, Niagara Falls
- Operations Research, St. Catharines
- Optical in Real Canadian Superstore, St. Catharines
- Optical in Zehrs, Niagara Falls
- OraCare Dental, Niagara Falls
- Ostrowski John Dr, Niagara Falls
- Oxford Learning Niagara Falls, Niagara Falls
- Oxford Learning St.Catharines, St. Catharines
- Oxford Mills Factory Outlet, Cambridge
- Oxford Mills Factory Outlet, Hamilton
- Oxford Mills Factory Outlet, Waterloo