| City | County | 2026 Pop. ↓ |
|---|---|---|
| Oakton | Fairfax County | 37,378 |
| Orange | Orange County | 5,453 |
| One Loudoun | Loudoun County | 3,847 |
| Oak Grove | Loudoun County | 2,608 |
| Onancock | Accomack County | 1,178 |
| Occoquan | Prince William County | 1,086 |
| Opal | Culpeper County | 805 |
| Onley | Accomack County | 542 |
| Oak Level | Franklin County | 501 |
| Osaka | Wise County | 106 |
| Oak Hall | Accomack County | 22 |