10 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Oakton | Fairfax County | 37,120 |
| Orange | Orange County | 5,333 |
| One Loudoun | Loudoun County | 3,474 |
| Oak Grove | Loudoun County | 2,722 |
| Onancock | Accomack County | 1,150 |
| Occoquan | Prince William County | 1,055 |
| Opal | Culpeper County | 772 |
| Onley | Accomack County | 532 |
| Oak Level | Franklin County | 352 |
| Osaka | Wise County | 128 |