15 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 |
| Amana | 5 | 584 | 472 | 1.57% | 589 | 1 | CDP |
| Middle Amana | 6 | 577 | 783 | -0.17% | 594 | 1 | CDP |
| Ladora | 7 | 221 | 229 | -0.9% | 749 | 0 | City |
| Parnell | 8 | 189 | 193 | -0.53% | 1,068 | 0 | City |
| South Amana | 9 | 149 | 111 | -0.67% | 108 | 1 | CDP |
| Millersburg | 10 | 134 | 136 | -0.74% | 1,098 | 0 | City |
| Homestead | 11 | 121 | 62 | -0.82% | 93 | 1 | CDP |
| High Amana | 12 | 86 | 73 | -2.27% | 225 | 0 | CDP |
| Conroy | 13 | 84 | 221 | -12.5% | 110 | 1 | CDP |
| West Amana | 14 | 59 | 122 | -7.81% | 217 | 0 | CDP |
| East Amana | 15 | 44 | 38 | 7.32% | 118 | 0 | CDP |
Williamsburg is the largest city in Iowa County, with a population of 3,387.
East Amana is the smallest city in Iowa County, with a population of 44.
There are 15 cities in Iowa County, Iowa.