St. Marys River (Florida–Georgia)
General data
- Name: St. Marys River (Florida–Georgia)
- Water system: Atlantic Ocean
- Water type: Distributary
- Source: Okefenokee Swamp
- Progression: Atlantic Ocean -> Planet Earth
- Climates: Temperate
- Continents: North America
- Countries: United States of America
The St. Marys River (named Saint Marys River by the United States Geological Survey) is a 126-mile-long (203 km) river in the southeastern United States. From near its source in the Okefenokee Swamp, to its mouth at the Atlantic Ocean, it forms a portion of the border between the U.S. states of Georgia and Florida