According to the United States Census Bureau, the town has a total area of 24.2 square miles (62.6 km²), of which 17.4 square miles (45.0 km²) is land and 6.8 square miles (17.6 km²), or 28.18%, is water.
The Mattapoisett River begins in Rochester and flows through town, emptying into Mattapoisett Harbor, an arm of Buzzards Bay.
 Mattapoisett is home to Haskell Swamp in the Tinkham Hill area in the northern part of town.
 There is also a state-managed wildlife area, Nasketucket Bay State Reservation, commonly known as Nunes Farm, along the waterfront near the Fairhaven line.
 There are four beaches and two parks along the waterfront, as well as Ned Point Light, which was built in 1837 and added to the National Register of Historic Places in 1987.
The town is home to the Fin, Fur and Feather Club, a hunt club and shooting range located along the Mattapoisett River off Crystal Spring Road.

Mattapoisett is the southwestern-most town of Plymouth County.
 It is bordered by Fairhaven to the southwest, Acushnet to the northwest, Rochester to the north, and Marion to the east.
 Buzzards Bay lies to the south.
 The town is 9 miles (14 km) east of New Bedford, 38 miles (61 km) east-southeast of Providence, Rhode Island, and 60 miles (97 km) south of Boston.
According to the United States Census Bureau, the town has a total area of 24.2 square miles (62.6 km²), of which 17.4 square miles (45.0 km²) is land and 6.8 square miles (17.6 km²), or 28.18%, is water. The Mattapoisett River begins in Rochester and flows through town, emptying into Mattapoisett Harbor, an arm of Buzzards Bay.  Mattapoisett is home to Haskell Swamp in the Tinkham Hill area in the northern part of town.  There is also a state-managed wildlife area, Nasketucket Bay State Reservation, commonly known as Nunes Farm, along the waterfront near the Fairhaven line.  There are four beaches and two parks along the waterfront, as well as Ned Point Light, which was built in 1837 and added to the National Register of Historic Places in 1987. The town is home to the Fin, Fur and Feather Club, a hunt club and shooting range located along the Mattapoisett River off Crystal Spring Road.
Mattapoisett is the southwestern-most town of Plymouth County.  It is bordered by Fairhaven to the southwest, Acushnet to the northwest, Rochester to the north, and Marion to the east.  Buzzards Bay lies to the south.  The town is 9 miles (14 km) east of New Bedford, 38 miles (61 km) east-southeast of Providence, Rhode Island, and 60 miles (97 km) south of Boston.
Mattapoisett, Massachusetts