South River is a borough in Middlesex County, New Jersey, situated in the central part of the state along the waterway that gives it its name. The South River forms the borough's western edge, with the Old Bridge Turnpike running along its east side, and the community sits near the Raritan River, the New Jersey Turnpike, and Route 18. Its population was about 16,118 at the 2020 census, spread across a compact borough that functions as one of central New Jersey's older, close-in communities. The borough's history is a story of municipal evolution. What is now South River began as the town of Washington, formed within East Brunswick Township in 1870, before incorporating as an independent borough in 1898. That transformation reflected the community's growth as a small industrial and residential center along the river, and its dense, pre-war street grid still reflects that era of development. Today South River is a diverse, family-oriented community with a PreK-12 public school district serving about 2,500 students. Local recreation centers on Daley's Pond Recreation Area and War Memorial Park, with the Raritan River and Raritan Bay nearby for boating and fishing. The borough's location places East Brunswick and Sayreville less than two miles away and puts New Brunswick within easy reach by bus, while the Turnpike and Route 18 open the broader region. Its older housing stock — single-family homes, twins, and multi-family buildings on compact lots — offers some of the more approachable options in the county. For buyers, South River offers a walkable, community-centered borough with practical access to Middlesex County's job centers and a long-established, river-named identity.