| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Manassas Park | 1 | 16,376 | 17,161 | -1.11% | 5,397 | 3 | City |
| Dumfries | 2 | 6,475 | 5,717 | 1.09% | 4,218 | 2 | Town |
| Haymarket | 3 | 1,614 | 1,537 | 0.75% | 2,812 | 1 | Town |
| Occoquan | 4 | 1,086 | 1,036 | 0.74% | 6,277 | 0 | Town |
| Quantico | 5 | 601 | 579 | 0.67% | 8,586 | 0 | Town |
Manassas Park is the largest city in Prince William County, with a population of 16,376.
Quantico is the smallest city in Prince William County, with a population of 601.
There are 5 cities in Prince William County, Virginia.