10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Franklin | 1 | 90,388 | 83,548 | 1.4% | 2,030 | 45 | City |
| Franklin | 2 | 90,388 | 84,155 | 1.4% | 2,030 | 45 | City |
| Brentwood | 3 | 45,544 | 45,384 | 0.04% | 1,081 | 42 | City |
| Brentwood | 4 | 45,544 | 45,447 | 0.04% | 1,081 | 42 | City |
| Nolensville | 5 | 16,247 | 13,829 | 2.77% | 1,556 | 10 | Town |
| Nolensville | 6 | 16,247 | 14,054 | 2.77% | 1,556 | 10 | Town |
| Fairview | 7 | 10,790 | 9,392 | 2.42% | 600 | 18 | City |
| Fairview | 8 | 10,790 | 9,515 | 2.42% | 600 | 18 | City |
| Thompson's Station | 9 | 9,463 | 7,438 | 4.21% | 410 | 23 | Town |
| Thompson's Station | 10 | 9,463 | 7,551 | 4.21% | 410 | 23 | Town |
Franklin is the largest city in Williamson County, with a population of 90,388.
Thompson's Station is the smallest city in Williamson County, with a population of 9,463.
There are 10 cities in Williamson County, Tennessee.