Founded in 1857, Clay County is one of 105 counties in the state of Kansas. Historically, Clay County was formed from unorganized area. The city of Clay Center is the county seat. With FIPS code of 27, Clay County has a population of 8,077 and area of 644 square miles (1,668 km2).
List of all cities in Clay County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Clay Center, KS | 67432 | 785 |
| Green, KS | 67447 | 785 |
| Longford, KS | 67458 | 785 |
| Morganville, KS | 67468 | 785 |
| Oakhill, KS | 67432 | 785 |
| Wakefield, KS | 67487 | 785 |