20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Granville | 1 | 2,769 | 2,777 | 0.58% | 62 | 45 | Township |
| Granville | 2 | 2,769 | 2,773 | 0.58% | 62 | 45 | Township |
| Granville | 3 | 1,324 | 1,359 | -0.53% | 1,013 | 1 | Village |
| Granville | 4 | 1,324 | 1,357 | -0.53% | 1,013 | 1 | Village |
| Hennepin | 5 | 1,249 | 1,238 | 0.81% | 30 | 41 | Township |
| Hennepin | 6 | 1,249 | 1,236 | 0.81% | 30 | 41 | Township |
| Magnolia | 7 | 1,023 | 1,010 | 1.09% | 24 | 42 | Township |
| Magnolia | 8 | 1,023 | 1,010 | 1.09% | 24 | 42 | Township |
| Hennepin | 9 | 744 | 760 | -0.4% | 140 | 5 | Village |
| Hennepin | 10 | 744 | 759 | -0.4% | 140 | 5 | Village |
| Senachwine | 11 | 637 | 612 | 1.27% | 20 | 32 | Township |
| Senachwine | 12 | 637 | 612 | 1.27% | 20 | 32 | Township |
| Mark | 13 | 504 | 517 | -0.59% | 473 | 1 | Village |
| Mark | 14 | 504 | 516 | -0.59% | 473 | 1 | Village |
| McNabb | 15 | 272 | 280 | -0.73% | 1,537 | 0 | Village |
| McNabb | 16 | 272 | 279 | -0.73% | 1,537 | 0 | Village |
| Magnolia | 17 | 253 | 258 | -0.39% | 808 | 0 | Village |
| Magnolia | 18 | 253 | 258 | -0.39% | 808 | 0 | Village |
| Standard | 19 | 220 | 227 | -0.9% | 309 | 1 | Village |
| Standard | 20 | 220 | 227 | -0.9% | 309 | 1 | Village |
Granville is the largest city in Putnam County, with a population of 2,769.
Standard is the smallest city in Putnam County, with a population of 220.
There are 20 cities in Putnam County, Illinois.