Mandeville
- County:
- St. Tammany Parish
- County Seat:
- No
- Area (mi²):
- 9.359
- State:
- Louisiana
Mandeville is a city located in St. Tammany Parish, Louisiana. Mandeville has a 2026 population of 12,973. Mandeville is currently declining at a rate of -0.17% annually but its population has increased by 1.15% since the most recent census, which recorded a population of 12,826 in 2020.