Founded in 1857, Clay County is one of 254 counties in the state of Texas. Historically, Clay County was formed from Cooke County. The city of Henrietta is the county seat. With FIPS code of 77, Clay County has a population of 10,263 and area of 1,098 square miles (2,844 km2).
List of all cities in Clay County, TX alphabetically
| City/Town | Postal Code | Area Code |
| Bellevue, TX | 76228 | 940 |
| Bluegrove, TX | 76352 | 940 |
| Byers, TX | 76357 | 940 |
| Henrietta, TX | 76365 | 940 |
| Petrolia, TX | 76377 | 940 |