8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Greencastle | 1 | 9,926 | 9,815 | 0.22% | 1,904 | 5.21 | City |
| Putnamville | 2 | 2,725 | 0 | 7.16% | 1,316 | 2.07 | CDP |
| Cloverdale | 3 | 2,218 | 2,052 | 1.51% | 636 | 3.49 | Town |
| Roachdale | 4 | 875 | 840 | 0.81% | 1,726 | 0.51 | Town |
| Bainbridge | 5 | 720 | 684 | 0.98% | 1,796 | 0.40 | Town |
| Coatesville | 6 | 576 | 555 | 0.7% | 882 | 0.65 | Town |
| Fillmore | 7 | 559 | 534 | 0.9% | 287 | 1.95 | Town |
| Russellville | 8 | 318 | 302 | 0.95% | 1,582 | 0.20 | Town |
Greencastle is the largest city in Putnam County, with a population of 9,926.
Russellville is the smallest city in Putnam County.
There are 8 cities in Putnam County, Indiana.