8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Zionsville | 1 | 33,665 | 30,837 | 1.71% | 501 | 67.19 | Town |
| Lebanon | 2 | 17,610 | 16,715 | 1.03% | 1,018 | 17.31 | City |
| Whitestown | 3 | 14,849 | 10,349 | 6.45% | 950 | 15.63 | Town |
| Thorntown | 4 | 1,406 | 1,431 | -0.35% | 2,294 | 0.61 | Town |
| Lake Holiday | 5 | 1,385 | 1,376 | 2.37% | 535 | 2.59 | CDP |
| Jamestown | 6 | 957 | 942 | 0.31% | 1,069 | 0.90 | Town |
| Advance | 7 | 507 | 502 | 0.2% | 861 | 0.59 | Town |
| Ulen | 8 | 112 | 114 | 0% | 491 | 0.23 | Town |
Zionsville is the largest city in Boone County, with a population of 33,665.
Ulen is the smallest city in Boone County.
There are 8 cities in Boone County, Indiana.