Southport is a census-designated place in the town of Fairfield, Connecticut. It is located along Long Island Sound between Mill River and Sasco Brook, where it borders Westport. As of the 2020 census, it had a population of 1,710. Settled in 1639, Southport center has been designated a local historic district since 1967. In 1971, it was listed on the National Register of Historic Places as the Southport Historic District.