15 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Williamsburg | 1 | 3,348 | 3,355 | -0.03% | 993 | 3.37 | City |
| Marengo | 2 | 2,381 | 2,438 | -0.46% | 1,126 | 2.12 | City |
| North English | 3 | 1,014 | 1,066 | -0.98% | 1,671 | 0.61 | City |
| Victor | 4 | 838 | 873 | -0.83% | 1,742 | 0.48 | City |
| Amana | 5 | 584 | 472 | 1.57% | 589 | 0.99 | CDP |
| Middle Amana | 6 | 577 | 783 | -0.17% | 594 | 0.97 | CDP |
| Ladora | 7 | 220 | 229 | -0.9% | 746 | 0.29 | City |
| Parnell | 8 | 186 | 193 | -0.53% | 1,051 | 0.18 | City |
| South Amana | 9 | 149 | 111 | -0.67% | 108 | 1.39 | CDP |
| Millersburg | 10 | 137 | 136 | 0% | 1,123 | 0.12 | City |
| Homestead | 11 | 121 | 62 | -0.82% | 93 | 1.30 | CDP |
| High Amana | 12 | 86 | 73 | -2.27% | 225 | 0.38 | CDP |
| Conroy | 13 | 84 | 221 | -12.5% | 110 | 0.76 | CDP |
| West Amana | 14 | 59 | 122 | -7.81% | 217 | 0.27 | CDP |
| East Amana | 15 | 44 | 38 | 7.32% | 118 | 0.37 | CDP |
Williamsburg is the largest city in Iowa County, with a population of 3,348.
East Amana is the smallest city in Iowa County.
There are 15 cities in Iowa County, Iowa.