Middlesex -- U.S. County in Connecticut Population (2000): 155071 Housing Units (2000): 67285 Land area (2000): 369.262704 sq. miles (956.385973 sq. km) Water area (2000): 69.805970 sq. miles (180.796624 sq. km) Total area (2000): 439.068674 sq. miles (1137.182597 sq. km) Located within: Connecticut (CT), FIPS 09 Location: 41.449378 N, 72.539622 W Headwords: Middlesex Middlesex, CT Middlesex County Middlesex County, CT