| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Wilmington | 1 | 12,805 | 12,662 | 0.02% | 989 | 13 | City |
| Blanchester | 2 | 4,250 | 4,225 | 0% | 1,040 | 4 | Village |
| Sabina | 3 | 2,430 | 2,491 | -0.29% | 2,066 | 1 | Village |
| New Vienna | 4 | 1,101 | 1,122 | -0.45% | 1,373 | 1 | Village |
| Corwin | 5 | 542 | 493 | 1.5% | 1,647 | 0 | Village |
| Clarksville | 6 | 535 | 534 | -0.19% | 1,148 | 0 | Village |
| Martinsville | 7 | 402 | 411 | -0.5% | 1,089 | 0 | Village |
| Midland | 8 | 306 | 308 | -0.33% | 860 | 0 | Village |
| Port William | 9 | 218 | 222 | -0.46% | 2,000 | 0 | Village |
Wilmington is the largest city in Clinton County, with a population of 12,805.
Port William is the smallest city in Clinton County, with a population of 218.
There are 9 cities in Clinton County, Ohio.