26 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Osborne | 1 | 1,250 | 1,322 | -0.95% | 812 | 2 | City |
| Ross | 2 | 808 | 886 | -2.53% | 23 | 35 | Township |
| Downs | 3 | 756 | 803 | -1.05% | 675 | 1 | City |
| Natoma | 4 | 291 | 326 | -3.32% | 8 | 36 | Township |
| Natoma | 5 | 283 | 304 | -1.05% | 671 | 0 | City |
| Osborne | 6 | 216 | 220 | -0.92% | 6 | 34 | Township |
| Bethany | 7 | 140 | 150 | -1.41% | 4 | 36 | Township |
| Downs | 8 | 139 | 141 | -0.71% | 4 | 35 | Township |
| Sumner | 9 | 135 | 148 | -2.17% | 3 | 54 | Township |
| Penn | 10 | 118 | 135 | -4.07% | 3 | 46 | Township |
| Alton | 11 | 90 | 98 | -1.1% | 291 | 0 | City |
| Portis | 12 | 82 | 88 | -1.2% | 314 | 0 | City |
| Tilden | 13 | 66 | 73 | -2.94% | 2 | 41 | Township |
| Bloom | 14 | 62 | 66 | -1.59% | 1 | 54 | Township |
| Corinth | 15 | 43 | 47 | -2.27% | 1 | 35 | Township |
| Valley | 16 | 34 | 35 | 0% | 1 | 36 | Township |
| Delhi | 17 | 29 | 30 | 0% | 1 | 54 | Township |
| Hawkeye | 18 | 26 | 29 | -3.7% | 1 | 36 | Township |
| Jackson | 19 | 26 | 29 | -3.7% | 1 | 36 | Township |
| Round Mound | 20 | 25 | 28 | -3.85% | 1 | 36 | Township |
| Grant | 21 | 21 | 24 | -4.55% | 1 | 35 | Township |
| Mount Ayr | 22 | 18 | 21 | -5.26% | 1 | 36 | Township |
| Hancock | 23 | 15 | 18 | -6.25% | 0.00 | 36 | Township |
| Victor | 24 | 12 | 12 | 0% | 0.00 | 36 | Township |
| Covert | 25 | 10 | 10 | 0% | 0.00 | 36 | Township |
| Kill Creek | 26 | 9 | 9 | 0% | 0.00 | 36 | Township |
Osborne is the largest city in Osborne County, with a population of 1,250.
Kill Creek is the smallest city in Osborne County, with a population of 9.
There are 26 cities in Osborne County, Kansas.