| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Emporia | 1 | 24,171 | 24,101 | 0.14% | 1,954 | 12 | City |
| Americus | 2 | 781 | 776 | -0.13% | 721 | 1 | City |
| Olpe | 3 | 531 | 517 | 0.38% | 756 | 1 | City |
| Hartford | 4 | 361 | 354 | 0.28% | 912 | 0 | City |
| Neosho Rapids | 5 | 238 | 236 | 0% | 471 | 1 | City |
| Reading | 6 | 183 | 181 | 0% | 859 | 0 | City |
| Allen | 7 | 163 | 161 | 0% | 591 | 0 | City |
| Admire | 8 | 134 | 131 | 0% | 415 | 0 | City |
| Bushong | 9 | 28 | 28 | 0% | 184 | 0 | City |
Emporia is the largest city in Lyon County, with a population of 24,171.
Bushong is the smallest city in Lyon County, with a population of 28.
There are 9 cities in Lyon County, Kansas.