24 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Osage City | 1 | 2,787 | 2,854 | -0.46% | 885 | 3.15 | City |
| Ridgeway township | 2 | 2,423 | 2,392 | 0.58% | 58 | 41.70 | Township |
| Elk township | 3 | 1,853 | 1,819 | 0.82% | 34 | 54.13 | Township |
| Burlingame township | 4 | 1,744 | 1,718 | 0.63% | 24 | 72.09 | Township |
| Valley Brook township | 5 | 1,530 | 1,506 | 0.39% | 38 | 40.17 | Township |
| Carbondale | 6 | 1,298 | 1,348 | -0.76% | 1,776 | 0.73 | City |
| Junction township | 7 | 1,288 | 1,198 | 2.14% | 26 | 49.78 | Township |
| Scranton township | 8 | 1,139 | 1,112 | 0.89% | 32 | 35.59 | Township |
| Lyndon | 9 | 1,039 | 1,039 | 0% | 1,165 | 0.89 | City |
| Overbrook | 10 | 970 | 1,004 | -0.72% | 1,783 | 0.54 | City |
| Vassar | 11 | 970 | 865 | 3.08% | 200 | 4.86 | CDP |
| Burlingame | 12 | 945 | 969 | -0.53% | 1,069 | 0.88 | City |
| Melvern township | 13 | 762 | 742 | 0.93% | 17 | 44.71 | Township |
| Fairfax township | 14 | 650 | 614 | 1.88% | 15 | 43.31 | Township |
| Scranton | 15 | 642 | 649 | -0.16% | 596 | 1.08 | City |
| Agency township | 16 | 418 | 416 | 0% | 13 | 33.15 | Township |
| Melvern | 17 | 345 | 354 | -0.58% | 969 | 0.36 | City |
| Grant township | 18 | 322 | 300 | 2.22% | 9 | 36.19 | Township |
| Quenemo | 19 | 286 | 288 | 0% | 644 | 0.44 | City |
| Superior township | 20 | 261 | 246 | 1.56% | 7 | 36.15 | Township |
| Olivet township | 21 | 247 | 224 | 3.35% | 4 | 55.67 | Township |
| Dragoon township | 22 | 220 | 203 | 2.33% | 6 | 36.25 | Township |
| Barclay township | 23 | 162 | 152 | 1.89% | 3 | 48.13 | Township |
| Arvonia township | 24 | 110 | 107 | 0.92% | 3 | 43.31 | Township |
Osage City is the largest city in Osage County, with a population of 2,787.
Arvonia township is the smallest city in Osage County.
There are 24 cities in Osage County, Kansas.