23 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Osage City | 1 | 2,770 | 2,856 | -0.5% | 880 | 3 | City |
| Ridgeway | 2 | 2,351 | 2,390 | -0.55% | 56 | 42 | Township |
| Elk | 3 | 1,803 | 1,822 | -0.33% | 33 | 54 | Township |
| Burlingame | 4 | 1,690 | 1,719 | -0.65% | 23 | 72 | Township |
| Valley Brook | 5 | 1,515 | 1,504 | 0.07% | 38 | 40 | Township |
| Carbondale | 6 | 1,284 | 1,349 | -0.85% | 1,756 | 1 | City |
| Junction | 7 | 1,226 | 1,198 | -0.08% | 25 | 50 | Township |
| Scranton | 8 | 1,098 | 1,114 | -0.63% | 31 | 36 | Township |
| Lyndon | 9 | 1,037 | 1,037 | 0% | 1,163 | 1 | City |
| Overbrook | 10 | 983 | 1,027 | -0.71% | 1,807 | 1 | City |
| Burlingame | 11 | 925 | 966 | -0.75% | 1,046 | 1 | City |
| Melvern | 12 | 737 | 741 | -0.41% | 16 | 45 | Township |
| Scranton | 13 | 635 | 652 | -0.47% | 590 | 1 | City |
| Fairfax | 14 | 622 | 613 | -0.16% | 14 | 43 | Township |
| Agency | 15 | 415 | 415 | -0.24% | 13 | 33 | Township |
| Melvern | 16 | 341 | 353 | -0.58% | 958 | 0 | City |
| Grant | 17 | 299 | 300 | -0.99% | 8 | 36 | Township |
| Quenemo | 18 | 286 | 288 | 0% | 644 | 0 | City |
| Superior | 19 | 246 | 245 | -0.81% | 7 | 36 | Township |
| Olivet | 20 | 228 | 223 | 0% | 4 | 56 | Township |
| Dragoon | 21 | 204 | 203 | -0.97% | 6 | 36 | Township |
| Barclay | 22 | 153 | 152 | -0.65% | 3 | 48 | Township |
| Arvonia | 23 | 111 | 107 | 0.91% | 3 | 43 | Township |
Osage City is the largest city in Osage County, with a population of 2,770.
Arvonia is the smallest city in Osage County, with a population of 111.
There are 23 cities in Osage County, Kansas.