Resident Population in New Haven County, CT was 863.70000 Thous. of Persons in January of 2021, according to the United States Federal Reserve. Historically, Resident Population in New Haven County, CT reached a record high of 864.73200 in January of 2012 and a record low of 744.94800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in New Haven County, CT - last updated from the United States Federal Reserve on May of 2024.