7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Vandalia | 1 | 7,309 | 7,456 | -0.33% | 897 | 8 | City |
| St. Elmo | 2 | 1,231 | 1,267 | -0.49% | 830 | 1 | City |
| Ramsey | 3 | 886 | 913 | -0.45% | 797 | 1 | Village |
| Brownstown | 4 | 672 | 693 | -0.44% | 881 | 1 | Village |
| Farina | 5 | 525 | 542 | -0.57% | 360 | 1 | Village |
| St. Peter | 6 | 308 | 320 | -0.65% | 591 | 1 | Village |
| Bingham | 7 | 60 | 62 | 0% | 219 | 0 | Village |
Vandalia is the largest city in Fayette County, with a population of 7,309.
Bingham is the smallest city in Fayette County, with a population of 60.
There are 7 cities in Fayette County, Illinois.