Founded in 1860, Marion County is one of 254 counties in the state of Texas. Historically, Marion County was formed from Cass County. The city of Jefferson is the county seat. With FIPS code of 315, Marion County has a population of 9,645 and area of 381 square miles (987 km2).
List of all cities in Marion County, TX alphabetically
| City/Town | Postal Code | Area Code |
| Berea, TX | 75657 | 903/430 |
| Gray, TX | 75657 | 903/430 |
| Jefferson, TX | 75657 | 903/430 |
| Lodi, TX | 75564 | 903/430 |
| Smithland, TX | 75657 | 903/430 |