3 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ashland | 1 | 20,935 | 21,589 | -0.62% | 1,950 | 11 | City |
| Catlettsburg | 2 | 1,715 | 1,764 | -0.58% | 1,286 | 1 | City |
| Bellefonte | 3 | 875 | 912 | -0.91% | 993 | 1 | City |
Ashland is the largest city in Boyd County, with a population of 20,935.
Bellefonte is the smallest city in Boyd County, with a population of 875.
There are 3 cities in Boyd County, Kentucky.