26 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Springfield | 1 | 57,912 | 58,590 | -0.19% | 2,174 | 27 | City |
| Springfield | 2 | 36,234 | 35,776 | 0.62% | 2,224 | 16 | Township |
| Springfield | 3 | 27,214 | 27,014 | 0.2% | 1,264 | 22 | Township |
| Springfield | 4 | 14,243 | 14,160 | 0.26% | 974 | 15 | Township |
| Moorefield | 5 | 12,609 | 12,633 | 0.21% | 422 | 30 | Township |
| Springfield | 6 | 12,272 | 12,326 | 0.16% | 405 | 30 | Township |
| Springfield | 7 | 11,054 | 11,101 | -0.09% | 302 | 37 | Township |
| Mad River | 8 | 10,967 | 10,991 | 0.2% | 331 | 33 | Township |
| German | 9 | 7,597 | 7,578 | 0.26% | 230 | 33 | Township |
| Springfield | 10 | 6,747 | 6,777 | 0% | 202 | 33 | Township |
| New Carlisle | 11 | 5,487 | 5,559 | -0.22% | 2,046 | 3 | City |
| Springfield | 12 | 5,452 | 5,481 | -0.13% | 294 | 19 | Township |
| Pike | 13 | 3,736 | 3,733 | 0.24% | 101 | 37 | Township |
| Harmony | 14 | 3,633 | 3,639 | 0.19% | 72 | 51 | Township |
| Springfield | 15 | 3,396 | 3,453 | -0.29% | 93 | 37 | Township |
| Pleasant | 16 | 3,136 | 3,127 | 0.26% | 76 | 42 | Township |
| Springfield | 17 | 2,987 | 3,034 | -0.13% | 83 | 36 | Township |
| Springfield | 18 | 2,535 | 2,609 | -0.59% | 83 | 30 | Township |
| Enon | 19 | 2,439 | 2,466 | -0.16% | 1,885 | 1 | Village |
| Springfield | 20 | 1,942 | 2,005 | -0.31% | 63 | 31 | Township |
| South Charleston | 21 | 1,688 | 1,709 | -0.18% | 1,369 | 1 | Village |
| North Hampton | 22 | 449 | 457 | -0.22% | 1,166 | 0 | Village |
| South Vienna | 23 | 405 | 411 | -0.25% | 622 | 1 | Village |
| Tremont City | 24 | 343 | 352 | -0.29% | 1,552 | 0 | Village |
| Donnelsville | 25 | 255 | 260 | -0.39% | 802 | 0 | Village |
| Catawba | 26 | 240 | 245 | -0.41% | 1,039 | 0 | Village |
Springfield is the largest city in Clark County, with a population of 57,912.
Catawba is the smallest city in Clark County, with a population of 240.
There are 26 cities in Clark County, Ohio.