7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Decorah | 1 | 7,422 | 7,581 | -0.43% | 1,025 | 7 | City |
| Calmar | 2 | 1,091 | 1,134 | -0.82% | 972 | 1 | City |
| Ossian | 3 | 771 | 801 | -0.77% | 722 | 1 | City |
| Spillville | 4 | 367 | 387 | -1.08% | 836 | 0 | City |
| Fort Atkinson | 5 | 297 | 309 | -1% | 934 | 0 | City |
| Ridgeway | 6 | 258 | 271 | -1.15% | 342 | 1 | City |
| Castalia | 7 | 139 | 146 | -1.42% | 240 | 1 | City |
Decorah is the largest city in Winneshiek County, with a population of 7,422.
Castalia is the smallest city in Winneshiek County, with a population of 139.
There are 7 cities in Winneshiek County, Iowa.