7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hamilton | 1 | 6,971 | 6,923 | 0.14% | 183 | 38.06 | City |
| Winfield | 2 | 4,874 | 4,861 | 0.06% | 274 | 17.78 | City |
| Guin | 3 | 2,120 | 2,187 | -0.61% | 142 | 14.97 | City |
| Hackleburg | 4 | 1,444 | 1,428 | 0.21% | 95 | 15.28 | Town |
| Bear Creek | 5 | 1,068 | 1,038 | 0.56% | 78 | 13.63 | Town |
| Brilliant | 6 | 827 | 834 | -0.12% | 78 | 10.59 | Town |
| Twin | 7 | 358 | 360 | 0% | 106 | 3.38 | Town |
Hamilton is the largest city in Marion County, with a population of 6,971.
Twin is the smallest city in Marion County.
There are 7 cities in Marion County, Alabama.