9 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bluefield | 1 | 9,048 | 9,608 | -1.22% | 1,008 | 8.97 | City |
| Princeton | 2 | 5,506 | 5,845 | -1.22% | 1,827 | 3.01 | City |
| Bluewell | 3 | 2,415 | 2,740 | 0.63% | 537 | 4.50 | CDP |
| Brush Fork | 4 | 1,138 | 1,025 | -0.35% | 599 | 1.90 | CDP |
| Athens | 5 | 924 | 968 | -0.96% | 2,293 | 0.40 | Town |
| Lashmeet | 6 | 760 | 473 | 2.43% | 1,013 | 0.75 | CDP |
| Montcalm | 7 | 711 | 582 | -0.14% | 260 | 2.73 | CDP |
| Bramwell | 8 | 259 | 274 | -1.15% | 467 | 0.56 | Town |
| Oakvale | 9 | 129 | 133 | -0.77% | 309 | 0.42 | Town |
Bluefield is the largest city in Mercer County, with a population of 9,048.
Oakvale is the smallest city in Mercer County.
There are 9 cities in Mercer County, West Virginia.