Mattapoisett River
General data
- Name: Mattapoisett River
- Water system: Atlantic Ocean
- Water type: River
- Progression: Mattapoisett Harbor -> Buzzards Bay -> Atlantic Ocean -> Planet Earth
- Climates: Continental
- Continents: North America
- Countries: United States of America
The Mattapoisett River is an 11.6-mile-long (18.7 km) river in southeastern Massachusetts, in the United States.
The river begins at Snipatuit Pond in Rochester and flows generally southwards through Mattapoisett to empty into Mattapoisett Harbor, an arm of Buzzards Bay. It flows through wetlands during much of its course.