Founded in 1855, Riley County is one of 105 counties in the state of Kansas. Historically, Riley County was one of the original 36 counties. The city of Manhattan is the county seat. With FIPS code of 161, Riley County has a population of 72,208 and area of 610 square miles (1,580 km2).
List of all cities in Riley County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Leonardville, KS | 66449 | 785 |
| Manhattan, KS | 66502 | 785 |
| 66503 | 785 | |
| 66505 | 785 | |
| 66506 | 785 | |
| Ogden, KS | 66517 | 785 |
| Randolph, KS | 66554 | 785 |
| Riley, KS | 66531 | 785 |