| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fairfax | 1 | 27,238 | 24,174 | 1.74% | 4,364 | 6 | City |
| Herndon | 2 | 25,649 | 24,585 | 0.56% | 5,984 | 4 | Town |
| Vienna | 3 | 16,724 | 16,451 | 0.2% | 3,798 | 4 | Town |
| Falls Church | 4 | 15,251 | 14,677 | 0.61% | 7,454 | 2 | City |
| Clifton | 5 | 241 | 240 | 0% | 984 | 0 | Town |
Fairfax is the largest city in Fairfax County, with a population of 27,238.
Clifton is the smallest city in Fairfax County, with a population of 241.
There are 5 cities in Fairfax County, Virginia.