18 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Center | 1 | 17,318 | 17,602 | -0.13% | 840 | 21 | Township |
| Frankfort | 2 | 16,341 | 16,695 | -0.36% | 1,660 | 10 | City |
| Ross | 3 | 2,834 | 2,814 | 0.32% | 96 | 30 | Township |
| Michigan | 4 | 1,545 | 1,560 | 0% | 43 | 36 | Township |
| Rossville | 5 | 1,515 | 1,509 | 0.07% | 3,301 | 0 | Town |
| Perry | 6 | 1,499 | 1,486 | 0.47% | 45 | 33 | Township |
| Kirklin | 7 | 1,233 | 1,232 | 0.16% | 35 | 35 | Township |
| Mulberry | 8 | 1,219 | 1,228 | -0.08% | 2,283 | 1 | Town |
| Jackson | 9 | 1,172 | 1,167 | 0.34% | 27 | 43 | Township |
| Union | 10 | 939 | 933 | 0.32% | 47 | 20 | Township |
| Owen | 11 | 898 | 896 | 0.22% | 36 | 25 | Township |
| Forest | 12 | 757 | 749 | 0.53% | 29 | 26 | Township |
| Kirklin | 13 | 710 | 710 | 0% | 1,686 | 0 | Town |
| Colfax | 14 | 702 | 704 | 0% | 1,897 | 0 | Town |
| Johnson | 15 | 455 | 455 | 0.22% | 17 | 27 | Township |
| Sugar Creek | 16 | 448 | 454 | -0.22% | 17 | 26 | Township |
| Michigantown | 17 | 417 | 435 | -0.71% | 1,539 | 0 | Town |
| Colfax | 18 | 174 | 166 | 0.58% | 5 | 37 | Township |
Center is the largest city in Clinton County, with a population of 17,318.
Colfax is the smallest city in Clinton County, with a population of 174.
There are 18 cities in Clinton County, Indiana.