Companies catalogue
- OAHF, Guelph
- OHSpros Inc., Edmonton
- OLiV Tasting Room, Edmonton
- ONroute Napanee (Westbound), Odessa
- OP Yoga, Kingston
- OSI Select Ready Foods Inc., Edmonton
- Oak+Olive Collective, Kitchener
- Oceanfood Sales Ltd, Vancouver
- Octave Theatre, Kingston
- Octavian Photography, Kitchener
- Odessa Non-Profit Housing Corporation, Odessa
- Odessa Travel Plaza, Odessa
- Odyssey Product Imports, Edmonton
- Off The Wall, Stratford Artist's Alliance, Stratford
- OfficeTeam, Waterloo
- Oil Changers, Kingston
- Oil Changers, Kingston
- Old Dominion Freight Line, Acheson
- Old Dominion Freight Line Inc, Edmonton
- Old Dutch Foods Ltd, Roseville
- Old Willow Green Community Garden, Kitchener
- Olde Bridge Place, West Montrose
- Oldphoneworks.com, Kingston
- Oliver Jill Dr, Kitchener
- On Bus Educatio, Kitchener
- On Front St. Bed & Breakfast, Saint Jacobs
- One Victoria, Waterloo
- Ongwanada Crescent Community Services, Kingston
- Ongwanada Resource Centre, Kingston
- Ontario Clean Water Agency, Lansdowne
- Ontario Coroner's Office, Kingston
- Ontario Correctional Svc Dept, Kingston
- Ontario Harm Reduction Distribution Program, Kingston
- Ontario Healthcare Housekeepers’ Association Inc., Bath
- Ontario Home Pros, Kitchener
- Ontario SPCA Lennox and Addington Animal Centre, Napanee
- Open Sesame, Kitchener
- Open Sky Ventures, Kitchener
- Our Lady Of Lourdes Church, Waterloo
- Our Lady of Fatima Catholic Church, Kitchener
- Our Lady of Grace School, Kitchener
- Our Lady of Mount Carmel Chapel & Academy, New Hamburg
- Our Place Family Resource & Early Years Centre, Kitchener
- Outcast Entertainment, Kingston
- Outpost Art Gallery, Kitchener
- Overeaters' Anonymous, Kingston
- Overeaters' Anonymous, Kingston
- Overland West Freight Lines Ltd, Edmonton
- Owers Chiropractic Office, Kitchener