| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Boone | 1 | 12,471 | 12,447 | 0% | 1,364 | 9 | City |
| Madrid | 2 | 2,825 | 2,801 | 0.18% | 2,308 | 1 | City |
| Ogden | 3 | 1,965 | 2,005 | -0.51% | 1,436 | 1 | City |
| Boxholm | 4 | 175 | 183 | -1.13% | 174 | 1 | City |
| Pilot Mound | 5 | 153 | 160 | -1.29% | 155 | 1 | City |
| Luther | 6 | 145 | 149 | -0.68% | 247 | 1 | City |
| Fraser | 7 | 108 | 103 | 0.93% | 95 | 1 | City |
| Beaver | 8 | 49 | 48 | 0% | 196 | 0 | City |
| Berkley | 9 | 21 | 22 | 0% | 104 | 0 | City |
Boone is the largest city in Boone County, with a population of 12,471.
Berkley is the smallest city in Boone County, with a population of 21.
There are 9 cities in Boone County, Iowa.