Ansonia is a city in New Haven County, Connecticut, United States, on the Naugatuck River, immediately north of Derby, and about 12 miles (19 km) northwest of New Haven. The population was 19,249 at the 2010 census. The ZIP code for Ansonia is 06401. The city is served by the Metro-North Railroad. Ansonia Station is a stop on the railroad passenger commuter service's Waterbury line, connecting to New York's Grand Central Terminal. Ansonia also is served by the Connecticut Transit bus carrier. Connecticut Route 8 serves Ansonia (Northbound, Exit 18; Southbound, Exit 19).
Ansonia, also referred to as "The Copper City", is recognized for its history of heavy machine manufacturing industry in the lower Naugatuck Valley. Production included copper, brass, rubber and plastics processing, molding and tubing, iron castings, sheet metal, electric, automatic screw machine, textiles, and foundry products. The well-known Ansonia Clock Company was founded here in 1851.