9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Emporia | 1 | 24,483 | 24,096 | 0.27% | 1,979 | 12 | City |
| Americus | 2 | 780 | 777 | 0.13% | 720 | 1 | City |
| Olpe | 3 | 534 | 516 | 0.56% | 761 | 1 | City |
| Hartford | 4 | 368 | 355 | 0.55% | 929 | 0 | City |
| Neosho Rapids | 5 | 241 | 234 | 0.42% | 477 | 1 | City |
| Reading | 6 | 185 | 182 | 0.54% | 869 | 0 | City |
| Allen | 7 | 167 | 161 | 0.6% | 605 | 0 | City |
| Admire | 8 | 139 | 133 | 0.72% | 430 | 0 | City |
| Bushong | 9 | 28 | 28 | 0% | 184 | 0 | City |
Emporia is the largest city in Lyon County, with a population of 24,483.
Bushong is the smallest city in Lyon County, with a population of 28.
There are 9 cities in Lyon County, Kansas.