14 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oelwein | 1 | 5,729 | 5,906 | -0.5% | 1,190 | 5 | City |
| West Union | 2 | 2,414 | 2,477 | -0.41% | 879 | 3 | City |
| Fayette | 3 | 1,163 | 1,252 | -1.27% | 777 | 1 | City |
| Elgin | 4 | 671 | 686 | -0.3% | 990 | 1 | City |
| Clermont | 5 | 568 | 577 | -0.18% | 451 | 1 | City |
| Maynard | 6 | 462 | 473 | -0.43% | 477 | 1 | City |
| Hawkeye | 7 | 424 | 439 | -0.47% | 631 | 1 | City |
| Arlington | 8 | 412 | 420 | -0.24% | 411 | 1 | City |
| Waucoma | 9 | 238 | 229 | 0.85% | 509 | 0 | City |
| Wadena | 10 | 198 | 206 | -0.5% | 263 | 1 | City |
| Westgate | 11 | 189 | 191 | 0% | 519 | 0 | City |
| St. Lucas | 12 | 167 | 167 | 0% | 657 | 0 | City |
| Randalia | 13 | 52 | 54 | 0% | 278 | 0 | City |
| Jackson Junction | 14 | 39 | 36 | 2.63% | 7 | 6 | City |
Oelwein is the largest city in Fayette County, with a population of 5,729.
Jackson Junction is the smallest city in Fayette County, with a population of 39.
There are 14 cities in Fayette County, Iowa.