New Haven is a city in the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut and is part of the New York City m…New Haven is a city in the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut and is part of the New York City metropolitan area. With a population of 134,023 as determined by the 2020 U.S. census, New Haven is the third largest city in Connecticut after Bridgeport and Stamford and the principal municipality of Greater New Haven, which had a total 2020 population of 864,835.