Founded in 1799, Williamson County is one of 95 counties in the state of Tennessee. Historically, Williamson County was formed from Davidson County. The city of Franklin is the county seat. With FIPS code of 187, Williamson County has a population of 255,735 and area of 582 square miles (1,507 km2).
List of all cities in Williamson County, TN alphabetically
| City/Town | Postal Code | Area Code |
| Allisona, TN | 37046 | 615 |
| Arrington, TN | 37014 | 615 |
| Bethesda, TN | 37046 | 615 |
| Brentwood, TN | 37024 | 615 |
| 37027 | 615 | |
| College Grove, TN | 37046 | 615 |
| Fairview, TN | 37062 | 615 |
| Franklin, TN | 37064 | 615 |
| 37065 | 615 | |
| 37067 | 615 | |
| 37068 | 615 | |
| 37069 | 615 | |
| Kingfield, TN | 37064 | 615 |
| Nolensville, TN | 37135 | 615 |
| Peytonsville, TN | 37064 | 615 |
| Primm Springs, TN | 38476 | 931 |
| Rudderville, TN | 37064 | 615 |
| Thompsons Station, TN | 37179 | 615 |
| Triune, TN | 37014 | 615 |