Setauket /səˈtɔːkɪt/ is a hamlet and census-designated place (CDP) in the Town of Brookhaven, Suffolk County, New York, United States, on the North Shore of Long Island. As of the 2010 United States census, the CDP population, which at the time included East Setauket as well, was 15,477. Setauket was founded in 1655, the first settlement in what would become the town of Brookhaven. Prior to the 2020 census, the community was part of the Setauket-East Setauket CDP. The area was split in 2020 into two separate CDPs: Setauket and East Setauket.