30 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Violet | 1 | 51,299 | 46,021 | 2.04% | 1,233 | 42 | Township |
| Lancaster | 2 | 41,931 | 40,631 | 0.62% | 2,202 | 19 | City |
| Pickerington | 3 | 26,457 | 23,240 | 2.49% | 2,595 | 10 | City |
| Bloom | 4 | 11,516 | 10,229 | 2.09% | 310 | 37 | Township |
| Liberty | 5 | 8,687 | 8,255 | 1.32% | 173 | 50 | Township |
| Walnut | 6 | 6,942 | 6,693 | 1.05% | 144 | 48 | Township |
| Pleasant | 7 | 6,459 | 6,195 | 1.14% | 187 | 35 | Township |
| Berne | 8 | 5,194 | 5,069 | 0.78% | 118 | 44 | Township |
| Hocking | 9 | 4,970 | 4,852 | 0.53% | 152 | 33 | Township |
| Clearcreek | 10 | 4,168 | 4,125 | 0.48% | 115 | 36 | Township |
| Rush Creek | 11 | 4,155 | 3,980 | 1.02% | 112 | 37 | Township |
| South Bloomfield | 12 | 4,146 | 2,149 | 10.65% | 1,037 | 4 | Village |
| Baltimore | 13 | 3,100 | 3,042 | 0.36% | 1,313 | 2 | Village |
| Lithopolis | 14 | 3,028 | 2,182 | 5.91% | 1,336 | 2 | Village |
| Amanda | 15 | 2,760 | 2,687 | 0.55% | 75 | 37 | Township |
| Richland | 16 | 2,397 | 2,340 | 0.71% | 97 | 25 | Township |
| Carroll | 17 | 2,070 | 2,107 | -0.29% | 61 | 34 | Township |
| Amanda | 18 | 2,049 | 2,069 | 0% | 62 | 33 | Township |
| Bremen | 19 | 1,527 | 1,492 | 0.46% | 1,774 | 1 | Village |
| Amanda | 20 | 1,052 | 1,065 | 0% | 38 | 28 | Township |
| Millersport | 21 | 996 | 979 | 0.3% | 1,071 | 1 | Village |
| Pleasantville | 22 | 956 | 944 | 0.21% | 3,528 | 0 | Village |
| Amanda | 23 | 681 | 666 | 0.44% | 2,148 | 0 | Village |
| Thurston | 24 | 610 | 608 | 0% | 1,510 | 0 | Village |
| Stoutsville | 25 | 580 | 580 | 0% | 502 | 1 | Village |
| Carroll | 26 | 500 | 502 | -0.2% | 795 | 1 | Village |
| Sugar Grove | 27 | 407 | 410 | -0.25% | 1,326 | 0 | Village |
| Rushville | 28 | 305 | 305 | 0% | 1,271 | 0 | Village |
| Darbyville | 29 | 189 | 186 | 0% | 366 | 1 | Village |
| West Rushville | 30 | 163 | 165 | -0.61% | 2,508 | 0 | Village |
Violet is the largest city in Fairfield County, with a population of 51,299.
West Rushville is the smallest city in Fairfield County, with a population of 163.
There are 30 cities in Fairfield County, Ohio.