- Occupational Health & Safety, Barrie
- Occupational Health Care Professionals, Barrie
- Occupational Therapy, Barrie - Occupational Health Specialists
- Office & Meeting Equipment & Supplies Rental, Barrie
- Office Buildings & Parks, Barrie
- Office Furniture & Equipment Rental & Leasing, Barrie
- Office Space on Rent, Barrie - Executive Suites, Meeting Rooms, Conference Rooms, Virtual Offices, etc
- Office Supplies, Equipment & Office Furniture Stores, Barrie
- Oil & Gas Companies, Barrie
- Oil And Petroleum Products, Barrie
- Oil Change & Lubrication, Barrie - Auto Oil & Quick Lube
- Optical Stores - Eyeglasses, Lenses & Sunglasses, Barrie
- Opticians, Barrie
- Optometrists, Barrie - Eye Doctors, Physicians & Surgeons (Optometry)
- Optometry Clinics, Barrie - Eye Clinics
- Organizing Services & Products – Household & Business, Barrie
- Oriental Restaurants, Barrie
- Ornamental Nursery, Barrie
- Ornamental Nursery Consultants, Barrie
|
- Ornamental Nursery Services, Barrie
- Orthodox Churches, Barrie
- Orthopedic & Prosthetic Appliances & Shoes, Barrie - Orthopedic Shoes
- Orthopedic Appliances, Barrie
- Other Building Materials & Supplies, Barrie
- Other Electrical Products, Barrie
- Other Industrial Contractors, Barrie
- Other Lodging, Barrie
- Outdoor Advertising & Billboard, Barrie
- Outdoor Equipment & Accessories, Barrie
- Outdoor Furniture, Barrie
- Outerwear Stores, Barrie - Jackets, Sunglasses, Hats, Caps, Coats, Gloves & More
- Outpatient Services, Barrie - Outpatient Care
- Overhead Door, Barrie
- Overhead Door Contractors, Barrie
- Overhead Doors Contractors, Barrie
- Ownership Organizations, Barrie
- Oxygen & Respiratory Equipment & Supplies, Barrie - Oxygen Concentrator, Tank, Machine, etc
|