| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Barnesville | 1 | 6,385 | 6,114 | 0.88% | 1,054 | 6 | City |
| Milner | 2 | 827 | 769 | 0.98% | 393 | 2 | City |
| Aldora | 3 | 197 | 167 | 2.6% | 779 | 0 | Town |
Barnesville is the largest city in Lamar County, with a population of 6,385.
Aldora is the smallest city in Lamar County, with a population of 197.
There are 3 cities in Lamar County, Georgia.