Illinois Cities — O
- Oquawka Dating
- Orangeville Dating
- Oraville Dating
- Orchard Heights Dating
- Orchard Mines Dating
- Orchardville Dating
- Oreana Dating
- Oregon Dating
- Orel Dating
- Orient Dating
- Orion Dating
- Orland Hills Dating
- Orland Park Dating
- Ormonde Dating
- Osceola Dating
- Osco Dating
- Oskaloosa Dating
- Ospur Dating
- Ossami Lake Dating
- Oswego Dating
- Otego Dating
- Ottawa Dating
- Otter Creek Dating
- Otterville Dating
- Otto Mall Dating
- Ottoville Dating
- Owaneco Dating
- Owego Dating
- Ozark Dating