Companies catalogue
- O'Brien & Anthony, St. John's
- O'Brien White, St. John's
- O'Brien's Boutique, Bay Bulls
- O'Brien's Drilling Services Inc., Torbay
- O'Brien's Music Inc., St. John's, Newfoundland and Labrador
- O'Connell H J Construction Ltd, St. John's
- O'Dea's Realty & Auction Room, St. John's
- O'Dea, Earle Law Offices, St. John's, Newfoundland and Labrador
- O'Flaherty Keir, St. John's
- O'Keefe Agencies, Mount Pearl
- O'Keefe Wade, Paradise
- O'Keefe's Flowers Ltd, St. John's
- O'Neill Nissan, Mount Pearl
- O'Neill's Gardenland, Spaniards Bay
- O'Regan Agencies Ltd, St. John's
- O'Regan Agencies Ltd, Bay Roberts
- O'Reillys Electrical Services, Conception Bay South
- O2 Planning + Design Inc., Calgary
- OGGI SPA Niagara, St. Catharines
- OJ'S Home Fashions, Mount Pearl
- OK Tire, Mount Pearl
- OPODD.COM, Mount Pearl
- Oak Run Transportation, Welland
- Oasis Construction Landscaping Ltd., Calgary
- Ocean Quest Adventures, St. John's, Newfoundland and Labrador
- Ocean Touch Instrumentation, St. John's
- Oceaneering Canada Limited, Houston
- Oceanex, St. John's
- Oceanex, St. John's
- Oceanic Consultants, St. John's
- Oceans Ltd, St. John's
- Office Furniture & Systems, Paradise
- Office Furniture Warehouse, St. John's
- Offshore Recruiting Services Inc, St. John's
- Ogunyemi Mary O, St. John's
- Oilfield Drilling Inc, Mount Pearl
- Old Church Antique Shop, Portugal Cove
- Old Navy, St. John's
- Old Port Massage Clinic, St. Catharines
- Olga McWilliam Benson, St. John's
- Olivia's Bridal, Mount Pearl
- Olliver's Fine Jewellery Inc, Calgary
- Olsen Europe, St. John's
- Olsen Law Office, Calgary
- Olympic Construction, St. John's
- Olympic Lawn Care, St. Catharines
- Oma Insurance, Paradise
- Omega Nail Salon & Spa, Grimsby
- On A Roll Cafe And Catering, Paradise
- On Side Restoration Services, St. John's
- On-Site Auto Glass, Mount Pearl
- Oncan Glass Ltd, St. Catharines
- One Floral, Lincoln
- One Of The Boys Barber Shop, Paradise
- Online Wedding, Engagement Rings and Bands store, Calgary
- Ontario Association Of Landscape Architects, Toronto
- Ontario Masonry Inc., St. Catharines
- Ontario Street Pharmacy, Saint Catharines
- Ontrack Computer Solutions Inc, Mount Pearl
- Opal + Onyx, St. John's, Newfoundland and Labrador
- Open Storage Solutions Inc, St. John's
- Operating Engineers College, Holyrood
- Optic Nerve Design: Niagara Web Design, Grimsby
- Optical Center, Hamilton
- Optical Center Inc, St. Catharines
- Optimus, Niagara-on-the-Lake
- Optique Boutique, St. John's, Newfoundland and Labrador
- Orangestore, Mount Pearl
- Orangestore, Paradise
- Orangestore, Witless Bay
- Orangestore, Conception Bay South
- Orangestore, Conception Bay South
- Orangestore, Conception Bay South
- Orangestore, St. John's
- Orangestore, St. John's
- Orangestore, St. John's
- Orchard Park Growers LTD., St. Catharines
- Organic Farm, Portugal Cove
- Oriental Hair Salon, St. John's
- Oriental Snow Mini Mart, St. John's
- Origami Owl - Jennifer Oltean, Independent Designer #200893537, Calgary
- Original Basket Boutique, Conception Bay South
- Orion Group, Inverness
- Orkin Canada, St. John's
- Ornamental, Calgary
- Ornamental Concrete Ltd., St. John's, Newfoundland and Labrador
- Ornamental Stone Inc., Rocky View No. 44
- OshKosh B'gosh, St. John's
- Osmond's Furniture, St. John's, Newfoundland and Labrador
- Osmond's Garage Ltd, Mount Pearl
- Otis Canada Inc, Farmington
- Otis Canada Inc, Farmington
- Outdoor Pros, Mount Pearl
- Outdoor Traditions Landscaping, Beamsville
- Outer Layer, Toronto
- Outsource - Virtual Office Services, Conception Bay South
- Outsource Bookkeeping, Conception Bay South
- Overhead Door (NFLD) Ltd., Mount Pearl
- Overhead Roofing, Mount Pearl
- Owen Myers Law Office, St. John's