14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oelwein | 1 | 5,758 | 5,906 | -0.52% | 1,196 | 5 | City |
| West Union | 2 | 2,424 | 2,477 | -0.45% | 882 | 3 | City |
| Fayette | 3 | 1,178 | 1,252 | -1.26% | 787 | 1 | City |
| Elgin | 4 | 673 | 686 | -0.44% | 993 | 1 | City |
| Clermont | 5 | 569 | 577 | -0.35% | 452 | 1 | City |
| Maynard | 6 | 464 | 473 | -0.43% | 479 | 1 | City |
| Hawkeye | 7 | 426 | 439 | -0.7% | 634 | 1 | City |
| Arlington | 8 | 413 | 420 | -0.48% | 412 | 1 | City |
| Waucoma | 9 | 236 | 229 | 0.43% | 504 | 0 | City |
| Wadena | 10 | 199 | 206 | -1% | 265 | 1 | City |
| Westgate | 11 | 189 | 191 | -0.53% | 519 | 0 | City |
| St. Lucas | 12 | 167 | 167 | 0% | 657 | 0 | City |
| Randalia | 13 | 52 | 54 | -1.89% | 278 | 0 | City |
| Jackson Junction | 14 | 38 | 36 | 0% | 6 | 6 | City |
Oelwein is the largest city in Fayette County, with a population of 5,758.
Jackson Junction is the smallest city in Fayette County, with a population of 38.
There are 14 cities in Fayette County, Iowa.