Cities
- Oak Bay BC
- Oak Bay NB
- Oak Bay QC
- Oak Bluff MB
- Oakbank MB
- Oakville MB
- Oakville NB
- Oakville ON
- Okotoks AB
- Oliver BC
- Oliver NS
- Onanole MB
- Onoway AB
- Orangeville ON
- Orford QC
- Orillia ON
- Oromocto NB
- Oshawa ON
- Osoyoos BC
- Ottawa ON
- Otterburn Park QC
- Otterburne MB
- Outlook ON
- Outlook SK
- Owen Sound ON
- Oxford NS