Ridgefield is a town in Fairfield County, Connecticut, United States. Situated in the foothills of the Berkshire Mountains, the 300-year-old community had a population of 23,643 at the 2000 census, spread across 35 square miles (91 km). In the 2000 census, the town center, which was formerly a borough, was defined by the U.S. Census Bureau as a census-designated place. Other named localities in the town are Titicus, near the New York state line, and Ridgebury, near the border with Danbury.