7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Williamsburg | 1 | 3,387 | 3,352 | 0.21% | 1,005 | 3 | City |
| Marengo | 2 | 2,409 | 2,438 | -0.25% | 1,139 | 2 | City |
| North English | 3 | 1,022 | 1,061 | -0.78% | 1,684 | 1 | City |
| Victor | 4 | 847 | 872 | -0.59% | 1,761 | 0 | City |
| Ladora | 5 | 221 | 229 | -0.9% | 749 | 0 | City |
| Parnell | 6 | 189 | 193 | -0.53% | 1,068 | 0 | City |
| Millersburg | 7 | 134 | 136 | -0.74% | 1,098 | 0 | City |
Williamsburg is the largest city in Iowa County, with a population of 3,387.
Millersburg is the smallest city in Iowa County, with a population of 134.
There are 7 cities in Iowa County, Iowa.