7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kingsport | 1 | 57,508 | 55,510 | 0.7% | 1,086 | 53 | City |
| Bristol | 2 | 28,038 | 27,181 | 0.61% | 857 | 33 | City |
| Blountville | 3 | 3,313 | 3,387 | 0.49% | 671 | 5 | CDP |
| Walnut Hill | 4 | 2,711 | 2,534 | 0.78% | 661 | 4 | CDP |
| Bluff City | 5 | 1,842 | 1,819 | 0.22% | 1,054 | 2 | City |
| Colonial Heights | 6 | 1,600 | 2,889 | -18.2% | 419 | 4 | CDP |
| Orebank | 7 | 1,052 | 778 | 7.13% | 1,194 | 1 | CDP |
Kingsport is the largest city in Sullivan County, with a population of 57,508.
Orebank is the smallest city in Sullivan County, with a population of 1,052.
There are 7 cities in Sullivan County, Tennessee.