Founded in 1876, Oldham County is one of 254 counties in the state of Texas. Historically, Oldham County was formed from Bexar County. The city of Vega is the county seat. With FIPS code of 359, Oldham County has a population of 1,717 and area of 1,501 square miles (3,888 km2).
List of all cities in Oldham County, TX alphabetically
| City/Town | Postal Code | Area Code |
| Adrian, TX | 79001 | 806 |
| Boys Ranch, TX | 79010 | 806 |
| Prayer Town, TX | 79010 | 806 |
| Valle de Oro, TX | 79010 | 806 |
| Vega, TX | 79092 | 806 |
| Wildorado, TX | 79098 | 806 |