7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Zionsville | 1 | 34,323 | 30,837 | 1.72% | 511 | 67 | Town |
| Lebanon | 2 | 18,054 | 16,716 | 1.25% | 845 | 21 | City |
| Whitestown | 3 | 16,671 | 10,350 | 6.75% | 1,050 | 16 | Town |
| Thorntown | 4 | 1,427 | 1,429 | 0% | 2,018 | 1 | Town |
| Jamestown | 5 | 975 | 941 | 0.62% | 930 | 1 | Town |
| Advance | 6 | 517 | 502 | 0.58% | 878 | 1 | Town |
| Ulen | 7 | 116 | 113 | 0.87% | 509 | 0 | Town |
Zionsville is the largest city in Boone County, with a population of 34,323.
Ulen is the smallest city in Boone County, with a population of 116.
There are 7 cities in Boone County, Indiana.