| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 6,777 | 6,942 | 0.12% | 178 | 38 | City |
| Winfield | 2 | 4,845 | 4,864 | 0.06% | 272 | 18 | City |
| Guin | 3 | 2,122 | 2,199 | -0.66% | 142 | 15 | City |
| Hackleburg | 4 | 1,472 | 1,434 | 0.48% | 96 | 15 | Town |
| Bear Creek | 5 | 1,058 | 1,037 | 0.38% | 78 | 14 | Town |
| Brilliant | 6 | 840 | 829 | 0.24% | 79 | 11 | Town |
| Twin | 7 | 350 | 353 | -0.28% | 104 | 3 | Town |
Hamilton is the largest city in Marion County, with a population of 6,777.
Twin is the smallest city in Marion County, with a population of 350.
There are 7 cities in Marion County, Alabama.