14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bainbridge township | 1 | 17,341 | 17,158 | 0.39% | 494 | 35.09 | Township |
| Greencastle township | 2 | 12,798 | 12,598 | 0.21% | 373 | 34.32 | Township |
| Greencastle | 3 | 9,926 | 9,815 | 0.22% | 1,904 | 5.21 | City |
| Floyd township | 4 | 4,321 | 4,112 | 0.98% | 128 | 33.87 | Township |
| Cloverdale township | 5 | 4,155 | 3,898 | 1.19% | 91 | 45.72 | Township |
| Cloverdale | 6 | 2,218 | 2,052 | 1.51% | 636 | 3.49 | Town |
| Jefferson township | 7 | 1,363 | 1,290 | 1.11% | 33 | 41.10 | Township |
| Jackson township | 8 | 912 | 864 | 1.11% | 26 | 34.56 | Township |
| Roachdale | 9 | 875 | 840 | 0.81% | 1,726 | 0.51 | Town |
| Russell township | 10 | 784 | 732 | 1.42% | 22 | 35.54 | Township |
| Bainbridge | 11 | 720 | 684 | 0.98% | 1,796 | 0.40 | Town |
| Coatesville | 12 | 576 | 555 | 0.7% | 882 | 0.65 | Town |
| Fillmore | 13 | 559 | 534 | 0.9% | 287 | 1.95 | Town |
| Russellville | 14 | 318 | 302 | 0.95% | 1,582 | 0.20 | Town |
Bainbridge township is the largest city in Putnam County, with a population of 17,341.
Russellville is the smallest city in Putnam County.
There are 14 cities in Putnam County, Indiana.