7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Demopolis | 1 | 6,515 | 7,142 | -1.57% | 367 | 18 | City |
| Linden | 2 | 1,758 | 1,928 | -1.57% | 491 | 4 | City |
| Thomaston | 3 | 304 | 325 | -0.98% | 151 | 2 | Town |
| Sweet Water | 4 | 210 | 228 | -1.41% | 89 | 2 | Town |
| Yellow Bluff | 5 | 204 | 225 | -1.45% | 326 | 1 | Town |
| Faunsdale | 6 | 79 | 87 | -1.25% | 285 | 0 | Town |
| Myrtlewood | 7 | 66 | 72 | -1.49% | 25 | 3 | Town |
Demopolis is the largest city in Marengo County, with a population of 6,515.
Myrtlewood is the smallest city in Marengo County, with a population of 66.
There are 7 cities in Marengo County, Alabama.