13 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Indian Trail | 1 | 44,757 | 40,304 | 2.03% | 1,963 | 23 | Town |
| Monroe | 2 | 41,396 | 34,685 | 3.35% | 1,321 | 31 | City |
| Waxhaw | 3 | 23,777 | 20,780 | 2.58% | 1,958 | 12 | Town |
| Stallings | 4 | 17,969 | 16,207 | 2% | 2,145 | 8 | Town |
| Wesley Chapel | 5 | 9,686 | 8,730 | 2.01% | 997 | 10 | Village |
| Unionville | 6 | 7,403 | 6,677 | 2% | 253 | 29 | Town |
| Marvin | 7 | 7,127 | 6,415 | 2.03% | 1,189 | 6 | Village |
| Wingate | 8 | 4,569 | 4,308 | 1.15% | 1,957 | 2 | Town |
| Lake Park | 9 | 3,651 | 3,303 | 1.93% | 4,967 | 1 | Village |
| Mineral Springs | 10 | 3,525 | 3,178 | 2% | 429 | 8 | Town |
| Marshville | 11 | 2,753 | 2,538 | 1.59% | 1,297 | 2 | Town |
| Hemby Bridge | 12 | 1,783 | 1,616 | 1.89% | 778 | 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 44,757.
JAARS is the smallest city in Union County, with a population of 959.
There are 13 cities in Union County, North Carolina.