Companies catalogue
- O'Brien's Clover Farm Supermarket, Cape Broyle
- O'Brien's Whale and Bird Tours, Bay Bulls
- O'Brien-Kelly Michael J, Calgary
- O'Fee Law, Calgary
- O'Leary Copywriting, St. John's
- O'Leva Olive Oils & Vinegars Gourmet Pantry, St. John's
- O'Neill & Son Plumbing & Heating, St. John's
- O'neill's Plumbing & Heating, Mount Pearl
- OK Tire, Bay Roberts
- OK Tire, Thunder Bay
- OT Painting & Plastering, St. John's
- Oakford Rental & Realty Co Ltd, St. John's
- Oasis Yoga & Wellness, St. John's
- Oberholtzer Design, St. John's
- Ocean Quest Spa, Conception Bay South
- Oceanview Crafts & Souvenirs, St. John's
- Octagon Development Corporation, St. John's
- Octagon Pharmachoice, Paradise
- Odyssey Mechanical Inc, Mount Pearl
- Off The Leash Animal Grooming, Mount Pearl
- Oil Filtration Solutions Ltd., Conception Bay South
- Old Dutch Foods LTD, Roseville
- Old Navy, Thunder Bay
- Old World LogCrafters Inc, Bauline
- Oliver POS, St. John's
- On the Go Tire, St. John's
- Once in a Lifetime Travel, Paradise
- One Percent Realty, St. John's
- One Stop Lube Shop Ltd, Thunder Bay
- One Stop Svc, Thunder Bay
- One to One Pharmacy Inc., Mount Pearl
- Ontario Crown Attorney, Thunder Bay
- Ooh La La Pet Spaw, Mount Pearl
- Opera on the Avalon, St. John's, Newfoundland and Labrador
- Orangestore, St. John's
- Orangestore, St. John's
- Orangestore, St. John's
- Orangetheory Fitness, St. John's, Newfoundland and Labrador
- Orthopedic Solutions, St. John's
- Orysi Aromatherapy & Body Care, Thunder Bay
- Oscar's Salvage, Kakabeka Falls
- OshKosh B'gosh, Thunder Bay
- Osuji & Smith, Calgary
- Other Ocean Group, St. John's, Newfoundland and Labrador
- Ottenheimer Baker, St. John's
- Outfitters Adventures, St. John's, Newfoundland and Labrador
- Owl Software, St. John's
- Oxford Market, Mount Pearl
- O’Brien Masonry Ltd., Logy Bay-Middle Cove-Outer Cove