Companies catalogue
- O Cantinho Churrasqueira & Cafe, Hamilton
- O'Dell Associates Inc., Burlington
- OLG Slots at Mohawk Racetrack, Milton
- Oak Park Chiropractic Centre, Oakville
- Oakridge Bible Chapel, Oakville
- Oakville (Town of), Oakville
- Oakville Building Svc Dept, Oakville
- Oakville Cardiologists, Oakville
- Oakville Cardiologists Diagnostic Centre, Oakville
- Oakville Chiropractic Centre, Oakville
- Oakville Chiropractic Life Centre, Oakville
- Oakville Christian School, Oakville
- Oakville Church of the Nazarene, Oakville
- Oakville Health, Oakville
- Oakville Kitchen & Bath Centre, Oakville
- Oakville Optihealth Clinic, Oakville
- Oakville Rehab Centre, Oakville
- Oakville Senior Citizens' Recreation Centre, Oakville
- Observe & Report Home Inspections, Hamilton
- Offord Centre for Child Studies, Hamilton
- Oil City Drywall Inc, Edmonton
- Olive and Oak | Fine and Custom Carpentry, Hamilton
- Oliver & Bonacini Café Grill, Oakville, Oakville
- Omagh Church Of Christ Milton Ontario, Milton
- On The Level Carpentry, Hamilton
- One James Cafe, Hamilton
- OnePlan Business Centres, Burlington
- Onesta Leasing a division of Onesta Capital Inc., Burlington
- Ontario Early Years Centres, Hamilton
- Ontario Ministry-Courts, Hamilton
- Ontario Mortgage Capital, Oakville
- Ontario Provincial Court, Burlington
- Ontario School Bus Association, Mississauga
- Osborne Human Capital Inc., Burlington
- Osmon's Authentic Mediterranean Restaurant, Oakville
- Ottawa Boot & Surplus Store, Hamilton
- Ottawa Street Business Improvement Area, Hamilton
- Our Dance Shop, Milton
- Our Lady Of All Souls Roman Catholic Church, Hamilton
- Our Lady Of The Angels Catholic Cemeteries, Hamilton
- Our Lady of Fatima Catholic Elementary School, Milton
- Our Lady of Lourdes Catholic Elementary School, Hamilton
- Our Lady of Mercy Catholic Church, Hamilton
- Our Lady of Mount Carmel Church, Hamilton
- Our Lady of Peace Catholic Elementary School, Hamilton
- Our Lady of Victory Catholic Elementary School, Milton
- Our Lady of the Assumption Catholic Elementary School, Hamilton
- Our Lady of the Assumption Parish, Stoney Creek
- Oxford College of Arts, Business, and Technology, Burlington