O
- Oak Bay
- Oakdale
- Oakdene Point
- Oakhill Forest
- Oak Lake
- Oak Leaf
- Oak Orchard
- Oak Point
- Oak Valley
- Oakview
- Oakview Beach
- Oakwood
- Obabikong Indian Reserve No. 35B
- Oceanview
- O'Connell
- O'Dell
- Odessa
- O'Donnell Landing
- Ogden
- Ogden's Beach
- Oil City
- Oil Springs
- Ojibway
- Ojibway Island
- Okanagan 1
- Okanagan Centre
- Okanagan Falls
- Okanagan Landing
- Okno
- Oldcastle
- Old Cut
- Oldenberg
- Old England
- Oldfield
- Old Fort
- Old Glenridge
- Old Woman's River
- O'Leary
- Olinda
- Oliphant
- Oliver
- Oliver
- Olivet
- Omeedjilawh Camp
- Omemee
- Omerville
- Oneida 41
- Orange Corners
- Oranmore
- Orchard Beach
- Orchard Point
- Orchardside
- Orchardville
- O'Reilly's Bridge
- Orford
- Oriel
- Orillia
- Oriole Parkway
- Orkney Beach
- Ormond
- Ormond Beach
- Ormsby
- Oro Beach
- Oro Lea Beach
- Oro-Medonte
- Oro Park
- Oro Station
- Orr Lake
- Orrville
- Orton
- Orwell
- Orwell
- Osnabruck Centre
- Osoyoos
- Osoyoos 1
- Osoyoos 3
- Ospringe
- Ossossane Beach
- Ostrander
- Ostryhon Corners
- Oswald
- Oswego Park
- Otonabee-South Monaghan
- Otter Creek
- Otter Falls
- Otter Lake
- Otter Lake 2
- Ottermere
- Otterville
- Otto
- Oungah
- Oustic
- Outlet
- Ouvry
- Overton
- Owenbrook
- Owen Sound
- Oxbow Park
- Oxenden
- Oxford Centre
- Oxford Mills
- Oxford Station
- Oxley
- Oxmead
- Oxtongue Lake
- Oyama
- Oyster Bed Bridge