Naugatuck, town (township) and borough, New Haven county, southwestern Connecticut, U.S. It lies along the Naugatuck River just south of Waterbury.

Settled as early as 1702 by Samuel Hickox from Waterbury, the locality was called Judd’s Meadows and, later, in 1734, South Farms. Following the organization of the Salem Ecclesiastical Society there in 1773, the locality was called Salem Bridge until it was incorporated from parts of Waterbury, Bethany, and Oxford as the town of Naugatuck (Algonquian: “One Large Tree,” in reference to a landmark tree) in 1844. The industrial borough of Naugatuck (established 1893) became coextensive with the town in 1895. Naugatuck includes Union City and part of the Naugatuck State Forest.

Abundant waterpower led to an early transition from farming to manufacturing, and the town’s basic rubber industry was established in 1843 by Charles Goodyear, who perfected the vulcanization process. The economy is now well diversified to include the production of chemicals, plastics, metals, and candy. Area 17 square miles (43 square km). Pop. (2000) 30,989; (2010) 31,862.