43 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Avon | 1 | 63,916 | 63,599 | 0.48% | 2,848 | 22 | Township |
| Cuba | 2 | 17,424 | 17,249 | 0.5% | 763 | 23 | Township |
| Canton | 3 | 13,706 | 14,245 | -0.52% | 395 | 35 | Township |
| Canton | 4 | 12,784 | 13,341 | -0.87% | 1,524 | 8 | City |
| Farmington | 5 | 3,078 | 3,203 | -0.48% | 86 | 36 | Township |
| Lewistown | 6 | 2,555 | 2,664 | -0.54% | 72 | 35 | Township |
| Farmington | 7 | 2,272 | 2,385 | -1% | 1,510 | 2 | City |
| Lewistown | 8 | 1,939 | 2,042 | -1.07% | 970 | 2 | City |
| Putman | 9 | 1,901 | 1,973 | -0.52% | 57 | 34 | Township |
| Buckheart | 10 | 1,269 | 1,316 | -0.47% | 37 | 35 | Township |
| Astoria | 11 | 1,185 | 1,238 | -0.67% | 33 | 36 | Township |
| Cuba | 12 | 1,125 | 1,182 | -1.06% | 2,072 | 1 | City |
| Astoria | 13 | 877 | 925 | -1.13% | 1,497 | 1 | Town |
| Vermont | 14 | 804 | 826 | -0.37% | 22 | 37 | Township |
| Pleasant | 15 | 694 | 720 | -0.43% | 19 | 37 | Township |
| Avon | 16 | 664 | 698 | -1.04% | 1,495 | 0 | Village |
| Fairview | 17 | 605 | 630 | -0.82% | 17 | 36 | Township |
| Vermont | 18 | 556 | 571 | -0.54% | 442 | 1 | Village |
| Liverpool | 19 | 547 | 563 | -0.55% | 14 | 40 | Township |
| Cass | 20 | 538 | 550 | 0% | 14 | 39 | Township |
| Young Hickory | 21 | 530 | 542 | 0% | 22 | 24 | Township |
| St. David | 22 | 499 | 526 | -1.19% | 1,545 | 0 | Village |
| Joshua | 23 | 423 | 431 | 0% | 12 | 35 | Township |
| Ipava | 24 | 422 | 442 | -0.94% | 1,575 | 0 | Village |
| Fairview | 25 | 406 | 426 | -0.98% | 96 | 4 | Village |
| Farmers | 26 | 350 | 363 | -0.28% | 10 | 36 | Township |
| London Mills | 27 | 340 | 350 | -0.58% | 497 | 1 | Village |
| Table Grove | 28 | 329 | 349 | -1.2% | 1,167 | 0 | Village |
| Banner | 29 | 315 | 317 | 0.32% | 11 | 28 | Township |
| Harris | 30 | 309 | 316 | 0% | 9 | 34 | Township |
| Dunfermline | 31 | 249 | 261 | -1.19% | 1,694 | 0 | Village |
| Bernadotte | 32 | 244 | 253 | -0.81% | 6 | 38 | Township |
| Smithfield | 33 | 183 | 188 | -0.54% | 394 | 0 | Village |
| Isabel | 34 | 169 | 174 | -0.59% | 6 | 29 | Township |
| Norris | 35 | 165 | 174 | -1.2% | 583 | 0 | Village |
| Bryant | 36 | 163 | 166 | -0.61% | 657 | 0 | Village |
| Waterford | 37 | 159 | 163 | -0.63% | 8 | 21 | Township |
| Banner | 38 | 157 | 160 | -0.63% | 122 | 1 | Village |
| Ellisville | 39 | 150 | 153 | 0% | 11 | 14 | Township |
| Marietta | 40 | 99 | 102 | -1% | 363 | 0 | Village |
| Liverpool | 41 | 90 | 94 | -1.1% | 1,071 | 0 | Village |
| Ellisville | 42 | 84 | 88 | -1.18% | 310 | 0 | Village |
| Kerton | 43 | 81 | 83 | 0% | 3 | 24 | Township |
Avon is the largest city in Fulton County, with a population of 63,916.
Kerton is the smallest city in Fulton County, with a population of 81.
There are 43 cities in Fulton County, Illinois.