10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Paris | 1 | 25,170 | 24,504 | 0.53% | 715 | 35 | City |
| Reno | 2 | 3,570 | 3,464 | 0.59% | 870 | 4 | City |
| Blossom | 3 | 1,497 | 1,401 | 1.29% | 586 | 3 | City |
| Powderly | 4 | 1,269 | 966 | 0.48% | 174 | 7 | CDP |
| Roxton | 5 | 556 | 549 | 0.18% | 644 | 1 | City |
| Deport | 6 | 549 | 551 | -0.18% | 494 | 1 | City |
| Petty | 7 | 197 | 95 | 7.07% | 342 | 1 | CDP |
| Toco | 8 | 93 | 92 | 0% | 547 | 0 | City |
| Sun Valley | 9 | 74 | 72 | 0% | 460 | 0 | City |
| Brookston | 10 | 49 | 53 | 6.52% | 67 | 1 | CDP |
Paris is the largest city in Lamar County, with a population of 25,170.
Brookston is the smallest city in Lamar County, with a population of 49.
There are 10 cities in Lamar County, Texas.