Founded in 1836, Johnson County is one of 95 counties in the state of Tennessee. Historically, Johnson County was formed from Carter County. The city of Mountain City is the county seat. With FIPS code of 91, Johnson County has a population of 18,170 and area of 299 square miles (774 km2).
List of all cities in Johnson County, TN alphabetically
| City/Town | Postal Code | Area Code |
| Butler, TN | 37640 | 423 |
| Laurel Bloomery, TN | 37680 | 423 |
| Mountain City, TN | 37683 | 423 |
| Shady Valley, TN | 37688 | 423 |
| Trade, TN | 37691 | 423 |