23 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fort Payne | 1 | 15,011 | 14,875 | 0.18% | 266 | 56.41 | City |
| Rainsville | 2 | 5,924 | 5,533 | 1.33% | 286 | 20.73 | City |
| Henagar | 3 | 2,309 | 2,298 | 0.09% | 102 | 22.61 | City |
| Carlisle-Rockledge | 4 | 2,256 | 2,530 | 0.36% | 139 | 16.20 | CDP |
| Whitesboro | 5 | 2,133 | 2,161 | 0% | 122 | 17.48 | CDP |
| Collinsville | 6 | 2,070 | 2,054 | 0.14% | 619 | 3.35 | Town |
| Crossville | 7 | 1,840 | 1,835 | 0.05% | 220 | 8.36 | Town |
| Sylvania | 8 | 1,817 | 1,797 | 0.22% | 213 | 8.52 | Town |
| Sardis City | 9 | 1,768 | 1,815 | -0.51% | 225 | 7.86 | Town |
| Fyffe | 10 | 984 | 978 | 0.1% | 198 | 4.97 | Town |
| Powell | 11 | 932 | 912 | 0.43% | 194 | 4.80 | Town |
| Geraldine | 12 | 914 | 911 | 0.11% | 239 | 3.82 | Town |
| New Union | 13 | 775 | 1,008 | -1.52% | 63 | 12.31 | CDP |
| Ider | 14 | 739 | 728 | 0.27% | 136 | 5.43 | Town |
| Ivalee | 15 | 640 | 733 | -2.44% | 86 | 7.45 | CDP |
| Valley Head | 16 | 596 | 580 | 0.51% | 158 | 3.77 | Town |
| Hammondville | 17 | 423 | 423 | 0% | 87 | 4.85 | Town |
| Shiloh | 18 | 330 | 325 | 0.3% | 155 | 2.13 | Town |
| Mentone | 19 | 326 | 323 | 0.31% | 76 | 4.29 | Town |
| Pine Ridge | 20 | 269 | 264 | 0.37% | 202 | 1.33 | Town |
| Lakeview | 21 | 163 | 162 | 0% | 252 | 0.65 | Town |
| Bristow Cove | 22 | 103 | 465 | -27.46% | 9 | 10.84 | CDP |
| Ridgeville | 23 | 82 | 84 | 0% | 100 | 0.82 | Town |
Fort Payne is the largest city in DeKalb County, with a population of 15,011.
Ridgeville is the smallest city in DeKalb County.
There are 23 cities in DeKalb County, Alabama.