Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lancaster | 1 | 41,684 | 40,636 | 0.63% | 2,189 | 19.0 | City |
| Pickerington | 2 | 25,921 | 23,260 | 2.63% | 2,543 | 10.2 | City |
| Blacklick Estates | 3 | 9,065 | 10,097 | 0.31% | 4,801 | 1.9 | CDP |
| Baltimore | 4 | 2,993 | 2,984 | 0.07% | 1,340 | 2.2 | Village |
| Beechwood Trails | 5 | 2,886 | 3,040 | -0.31% | 811 | 3.6 | CDP |
| Lithopolis | 6 | 2,884 | 2,180 | 6.5% | 1,273 | 2.3 | Village |
| South Bloomfield | 7 | 2,830 | 2,149 | 6.39% | 708 | 4.0 | Village |
| Bremen | 8 | 1,508 | 1,483 | 0.4% | 1,751 | 0.9 | Village |
| Fairfield Beach | 9 | 1,243 | 1,145 | -0.24% | 1,898 | 0.7 | CDP |
| Logan Elm Village | 10 | 1,240 | 1,021 | 0.65% | 3,416 | 0.4 | CDP |
| Thornport | 11 | 1,046 | 946 | 0.29% | 870 | 1.2 | CDP |
| Hide-A-Way Hills | 12 | 1,009 | 833 | 1.61% | 387 | 2.6 | CDP |
| Millersport | 13 | 974 | 978 | -0.1% | 1,047 | 0.9 | Village |
| Pleasantville | 14 | 953 | 945 | 0.21% | 3,517 | 0.3 | Village |
| Amanda | 15 | 683 | 670 | 0.44% | 2,155 | 0.3 | Village |
| Thurston | 16 | 604 | 607 | -0.17% | 1,495 | 0.4 | Village |
| Stoutsville | 17 | 576 | 579 | -0.17% | 498 | 1.2 | Village |
| Carroll | 18 | 499 | 502 | -0.2% | 793 | 0.6 | Village |
| Hamburg | 19 | 446 | 485 | 7.73% | 186 | 2.4 | CDP |
| Sugar Grove | 20 | 424 | 428 | -0.24% | 1,381 | 0.3 | Village |
| Jersey | 21 | 396 | 483 | 7.9% | 241 | 1.6 | CDP |
| Rushville | 22 | 303 | 306 | -0.33% | 1,263 | 0.2 | Village |
| Darbyville | 23 | 190 | 185 | 0.53% | 368 | 0.5 | Village |
| West Rushville | 24 | 165 | 165 | 0% | 2,538 | 0.1 | Village |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Lancaster is the largest city in Fairfield County.
West Rushville is the smallest city in Fairfield County.
There are 24 cities in Fairfield County, Ohio.