14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Jackson township | 1 | 23,432 | 23,208 | 0.39% | 680 | 34.44 | Township |
| Seymour | 2 | 21,690 | 21,629 | 0.06% | 1,788 | 12.13 | City |
| Brownstown township | 3 | 5,737 | 5,687 | 0.54% | 91 | 62.95 | Township |
| Redding township | 4 | 5,258 | 5,217 | 0.54% | 154 | 34.13 | Township |
| Brownstown | 5 | 3,005 | 3,025 | -0.13% | 1,856 | 1.62 | Town |
| Owen township | 6 | 1,611 | 1,575 | 0.94% | 30 | 54.52 | Township |
| Crothersville | 7 | 1,483 | 1,507 | -0.34% | 1,278 | 1.16 | Town |
| Carr township | 8 | 1,362 | 1,342 | 0.74% | 33 | 41.33 | Township |
| Driftwood township | 9 | 940 | 938 | 0.53% | 34 | 27.90 | Township |
| Grassy Fork township | 10 | 686 | 685 | 0.44% | 17 | 39.67 | Township |
| Medora | 11 | 626 | 638 | -0.32% | 2,059 | 0.30 | Town |
| Vallonia | 12 | 358 | 292 | 0.28% | 474 | 0.76 | CDP |
| Salt Creek township | 13 | 308 | 304 | 0.65% | 7 | 42.83 | Township |
| Freetown | 14 | 214 | 317 | -4.89% | 309 | 0.69 | CDP |
Jackson township is the largest city in Jackson County, with a population of 23,432.
Freetown is the smallest city in Jackson County.
There are 14 cities in Jackson County, Indiana.