The town has a total area of 25.5 square miles (66 km 2 ), of which 23.1 square miles (60 km 2 ) is land and 2.5 square miles (6.5 km 2 ), or 9.67%, is water. The town is bordered by Dighton on the northeast, Somerset on the east, Mount Hope Bay on the south, Warren, Rhode Island , on the southwest, Barrington, Rhode Island , on the west, and Seekonk and Rehoboth to the north. Part of the town's border with Somerset is made up of the Lees River . The Cole , Kickamuit and Palmer rivers also pass through the town on their way south to Mount Hope Bay (for the Kickamuit, Cole and Lees rivers) and Narragansett Bay (for the Palmer). The entire town is a part of the Narragansett Bay watershed area. The town's neighborhoods include Barneyville, North Swansea, Swansea Village, Birch Swamp Corner, Hortonville, Luther Corner, South Swansea, Touissett, Ocean Grove , and Smokerise. Swansea is 12 miles (19 km) southeast of Providence and 47 miles (76 km) south of Boston .
Much of the town's retail businesses are located along the highways, with the area around the junction of U.S. Route 6 and Massachusetts Route 118 being the location of Swansea Mall , a large single-level mall that is the center of the retail district. Just north of the mall are several office complexes, including the former headquarters of the First Federal Bank (now a division headquarters for Webster Bank, which bought it out), doctor's offices and Academic Management Services, a division of Sallie Mae . The area along Route 103 between the Lees River and the Cole River is also an area for retail, with many smaller businesses lining the road.
However, outside of the retail area (as well as the densely populated neighborhoods of Ocean Grove , South Swansea and Smokerise), much of the area is rural.