Demopolis
- County:
- Marengo County
- County Seat:
- No
- Area (mi²):
- 17.744
- State:
- Alabama
Demopolis is a city located in Marengo County, Alabama. Demopolis has a 2026 population of 6,724. Demopolis is currently declining at a rate of -1.42% annually and its population has decreased by -5.85% since the most recent census, which recorded a population of 7,142 in 2020.