13 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Indian Trail | 1 | 44,556 | 40,300 | 1.95% | 1,954 | 23 | Town |
| Monroe | 2 | 39,877 | 34,676 | 2.68% | 1,273 | 31 | City |
| Waxhaw | 3 | 24,602 | 20,779 | 3.21% | 2,026 | 12 | Town |
| Stallings | 4 | 17,887 | 16,199 | 1.93% | 2,135 | 8 | Town |
| Wesley Chapel | 5 | 9,648 | 8,728 | 1.94% | 993 | 10 | Village |
| Unionville | 6 | 7,363 | 6,673 | 1.91% | 252 | 29 | Town |
| Marvin | 7 | 7,085 | 6,405 | 1.96% | 1,182 | 6 | Village |
| Wingate | 8 | 4,509 | 4,091 | 1.9% | 1,931 | 2 | Town |
| Lake Park | 9 | 3,642 | 3,296 | 1.93% | 4,955 | 1 | Village |
| Mineral Springs | 10 | 3,513 | 3,178 | 1.94% | 428 | 8 | Town |
| Marshville | 11 | 2,740 | 2,540 | 1.48% | 1,291 | 2 | Town |
| Hemby Bridge | 12 | 1,774 | 1,616 | 1.84% | 774 | 2 | Town |
| JAARS | 13 | 959 | 1,090 | 2.57% | 1,116 | 1 | CDP |
Indian Trail is the largest city in Union County, with a population of 44,556.
JAARS is the smallest city in Union County, with a population of 959.
There are 13 cities in Union County, North Carolina.