5 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Manhattan | 1 | 54,974 | 54,151 | 0.25% | 2,696 | 20 | City |
| Ogden | 2 | 1,650 | 1,668 | -0.18% | 986 | 2 | City |
| Riley | 3 | 961 | 943 | 0.31% | 1,892 | 1 | City |
| Leonardville | 4 | 446 | 431 | 0.68% | 1,458 | 0 | City |
| Randolph | 5 | 157 | 159 | 0% | 571 | 0 | City |
Manhattan is the largest city in Riley County, with a population of 54,974.
Randolph is the smallest city in Riley County, with a population of 157.
There are 5 cities in Riley County, Kansas.