26 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Osborne | 1 | 1,262 | 1,322 | -0.94% | 820 | 2 | City |
| Ross | 2 | 829 | 886 | -2.47% | 23 | 35 | Township |
| Downs | 3 | 764 | 803 | -1.04% | 682 | 1 | City |
| Natoma | 4 | 301 | 326 | -3.22% | 8 | 36 | Township |
| Natoma | 5 | 286 | 304 | -1.38% | 678 | 0 | City |
| Osborne | 6 | 218 | 220 | -0.91% | 6 | 34 | Township |
| Bethany | 7 | 142 | 150 | -1.39% | 4 | 36 | Township |
| Downs | 8 | 140 | 141 | -0.71% | 4 | 35 | Township |
| Sumner | 9 | 138 | 148 | -2.13% | 3 | 54 | Township |
| Penn | 10 | 123 | 135 | -3.91% | 3 | 46 | Township |
| Alton | 11 | 91 | 98 | -2.15% | 294 | 0 | City |
| Portis | 12 | 83 | 88 | -1.19% | 318 | 0 | City |
| Tilden | 13 | 68 | 73 | -2.86% | 2 | 41 | Township |
| Bloom | 14 | 63 | 66 | -1.56% | 1 | 54 | Township |
| Corinth | 15 | 44 | 47 | -2.22% | 1 | 35 | Township |
| Valley | 16 | 34 | 35 | 0% | 1 | 36 | Township |
| Delhi | 17 | 29 | 30 | 0% | 1 | 54 | Township |
| Hawkeye | 18 | 27 | 29 | -3.57% | 1 | 36 | Township |
| Jackson | 19 | 27 | 29 | -3.57% | 1 | 36 | Township |
| Round Mound | 20 | 26 | 28 | -3.7% | 1 | 36 | Township |
| Grant | 21 | 22 | 24 | -4.35% | 1 | 35 | Township |
| Mount Ayr | 22 | 19 | 21 | -5% | 1 | 36 | Township |
| Hancock | 23 | 16 | 18 | -5.88% | 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 1,262.
Kill Creek is the smallest city in Osborne County, with a population of 9.
There are 26 cities in Osborne County, Kansas.