According to the United States Census Bureau, the town has a total area of 14.1 square miles (37 km2), of which 12.4 square miles (32 km2) is land and 1.7 square miles (4.4 km2), or 12.06%, is water. It is bordered by the river and New Bedford to the west, Acushnet to the north, Mattapoisett to the east and Buzzards Bay to the south. The town line with Mattapoisett lies along the Bristol and Plymouth county lines. The town is the southeastern corner of Bristol County, and contains the easternmost point of the county, on West Island. Fairhaven is approximately 54 miles (87 km) south of Boston, 21 miles (34 km) by land west of Cape Cod, and 32 miles (51 km) southeast of Providence, Rhode Island.
The town is located on Buzzards Bay, on the eastern bank of the Acushnet River at its mouth. The lands of the town jut out into the bay via Sconticut Neck and West Island, along with several other small islands. Most of the town’s water area consists of its harbors, bays and coves, along with a portion of the Acushnet’s waters, and Nasketucket and Scipping Creeks. The town lies along coastal plain, and has some swampland along the Nasketucket and around Boy’s and Girl’s Creeks, north of Priest’s Cove. Fairhaven’s localities include Fairhaven Center, North Fairhaven, East Fairhaven, Oxford, Poverty Point, Nasketucket, Sconticut Neck, and Winsegansett Heights. Most of the town’s population lies either in the west side of town, along Sconticut Neck or in the village of East Fairhaven, with the northeast quarter of the town’s land sparsely populated.
The town has two large public parks, Livesey Park and Cushman Park, as well as a number of smaller ones. Cushman Park, as well as having tennis courts and ballfields and a bandstand, is the location of Fairhaven High School‘s running track. The town has several commercial wharves, a yacht club, and several marinas for recreational craft. There are several small bathing beaches, the largest being the Fort Phoenix State Reservation, a south-facing beach to the east of the fort and the New Bedford Harbor Hurricane Barrier. There is also a bike path which travels along a long-unused railroad right-of-way, just to the south of Route 6.