5 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Morganfield | 1 | 3,100 | 3,253 | -0.99% | 1,102 | 3 | City |
| Breckinridge Center | 2 | 1,693 | 1,961 | -1.46% | 645 | 3 | CDP |
| Sturgis | 3 | 1,633 | 1,740 | -1.33% | 1,043 | 2 | City |
| Uniontown | 4 | 884 | 927 | -1.01% | 1,040 | 1 | City |
| Waverly | 5 | 299 | 313 | -0.99% | 1,120 | 0 | City |
Morganfield is the largest city in Union County, with a population of 3,100.
Waverly is the smallest city in Union County, with a population of 299.
There are 5 cities in Union County, Kentucky.