14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Oelwein | 1 | 5,714 | 5,906 | -0.66% | 1,187 | 4.81 | City |
| West Union | 2 | 2,402 | 2,476 | -0.62% | 874 | 2.75 | City |
| Fayette | 3 | 1,231 | 1,253 | -0.32% | 822 | 1.50 | City |
| Elgin | 4 | 666 | 686 | -0.6% | 982 | 0.68 | City |
| Clermont | 5 | 567 | 577 | -0.35% | 450 | 1.26 | City |
| Maynard | 6 | 464 | 473 | -0.43% | 479 | 0.97 | City |
| Hawkeye | 7 | 423 | 437 | -0.7% | 629 | 0.67 | City |
| Arlington | 8 | 416 | 421 | -0.24% | 415 | 1 | City |
| Waucoma | 9 | 225 | 229 | -0.44% | 481 | 0.47 | City |
| Wadena | 10 | 202 | 207 | -0.49% | 269 | 0.75 | City |
| Westgate | 11 | 189 | 191 | 0% | 519 | 0.36 | City |
| St. Lucas | 12 | 167 | 167 | 0% | 657 | 0.25 | City |
| Randalia | 13 | 49 | 51 | 0% | 262 | 0.19 | City |
| Jackson Junction | 14 | 40 | 37 | 2.56% | 7 | 5.96 | City |
Oelwein is the largest city in Fayette County, with a population of 5,714.
Jackson Junction is the smallest city in Fayette County.
There are 14 cities in Fayette County, Iowa.