Ontario Cities — O
- Oakland Dating
- Oakville Dating
- Oakwood Dating
- Oba Dating
- Odessa Dating
- Ogoki Dating
- Ohsweken Dating
- Oil City Dating
- Oil Springs Dating
- Oldcastle Dating
- Omemee Dating
- Ompah Dating
- Onaping Dating
- Opasatika Dating
- Orangeville Dating
- Orillia Dating
- Orleans Dating
- Oro Dating
- Oro Station Dating
- Orono Dating
- Orton Dating
- Osgoode Dating
- Oshawa Dating
- Osnaburgh House Dating
- Ottawa Dating
- Otterville Dating
- Owen Sound Dating
- Oxdrift Dating
- Oxford Mills Dating
- Oxford Station Dating