Gainesville Lake (Alabama)
General data
- Name: Gainesville Lake (Alabama)
- Water system: Mobile River
- Water type: Artificial lake
- Progression: Tennessee–Tombigbee Waterway (Tenn–Tom) -> Black Warrior River -> Tombigbee River -> Mobile River -> Mobile Bay -> Gulf of Mexico -> Atlantic Ocean -> Planet Earth
- Climates: Temperate
- Continents: North America
- Countries: United States of America
Gainesville Reservoir is a significant U.S. waterway on the Tennessee-Tombigbee Waterway in Alabama, formed by the Gainesville Lock and Dam, used for navigation and providing water quality data for the Tombigbee River, offering recreation and affecting local hydrology.