Beacon Falls is a town in western New Haven County, Connecticut, United States. The town is part of the Naugatuck Valley Planning Region & is around 6 miles from Waterbury. It lies in the southwestern part of the state, and is bisected by the Naugatuck River. The population was 6,000 at the 2020 census, down from 6,049 at the 2010 census.

New Haven County is a county in the south central part of the U.S. state of Connecticut. As of the 2020 census, the population was 864,835, making it the third-most populous county in Connecticut. Two of the state's top 5 largest cities, New Haven (3rd) and Waterbury (5th), are part of New Haven County.