Resident Population in Fairfield County, CT was 959.76800 Thous. of Persons in January of 2021, according to the United States Federal Reserve. Historically, Resident Population in Fairfield County, CT reached a record high of 959.76800 in January of 2021 and a record low of 786.50000 in January of 1973. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Fairfield County, CT - last updated from the United States Federal Reserve on May of 2024.