7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Decorah | 1 | 7,390 | 7,581 | -0.43% | 1,020 | 7 | City |
| Calmar | 2 | 1,083 | 1,134 | -0.73% | 964 | 1 | City |
| Ossian | 3 | 765 | 801 | -0.78% | 716 | 1 | City |
| Spillville | 4 | 363 | 387 | -1.09% | 827 | 0 | City |
| Fort Atkinson | 5 | 295 | 309 | -0.67% | 928 | 0 | City |
| Ridgeway | 6 | 256 | 271 | -0.78% | 339 | 1 | City |
| Castalia | 7 | 138 | 146 | -0.72% | 239 | 1 | City |
Decorah is the largest city in Winneshiek County, with a population of 7,390.
Castalia is the smallest city in Winneshiek County, with a population of 138.
There are 7 cities in Winneshiek County, Iowa.