Founded in 1876, Castro County is one of 254 counties in the state of Texas. Historically, Castro County was formed from Bexar County. The city of Dimmitt is the county seat. With FIPS code of 69, Castro County has a population of 7,374 and area of 898 square miles (2,326 km2).
List of all cities in Castro County, TX alphabetically
| City/Town | Postal Code | Area Code |
| Dimmitt, TX | 79027 | 806 |
| Hart, TX | 79043 | 806 |
| Nazareth, TX | 79063 | 806 |
| Summerfield, TX | 79085 | 806 |