15 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Opelika | Lee County | 35,988 |
| Oxford | Calhoun County | 22,088 |
| Ozark | Dale County | 14,376 |
| Orange Beach | Baldwin County | 8,716 |
| Oneonta | Blount County | 7,063 |
| Opp | Covington County | 6,695 |
| Odenville | St. Clair County | 5,899 |
| Owens Cross Roads | Madison County | 3,289 |
| Ohatchee | Calhoun County | 1,209 |
| Our Town | Coosa County | 762 |
| Oakman | Walker County | 750 |
| Oak Grove | Clay County | 591 |
| Onycha | Coffee County | 177 |
| Orrville | Dallas County | 137 |
| Oak Hill | Wilcox County | 9 |