Sag Harbor is an incorporated village in Suffolk County, New York, United States, with parts in both the Towns of East Hampton and Southampton. The population was 2,313 at the 2000 census. The entire business district of the whaling port and writer's colony is listed as Sag Harbor Village District on the National Register of Historic Places. Sag Harbor is about three fifths in Southampton and two fifths in East Hampton. The dividing line is Division Street which becomes Town Line Road just south of the village. Most of the defining landmarks of the village—including its Main Street, the Whalers Church, Jermain Library, Whaling Museum, the Old Burying Ground, Oakland Cemetery, Mashashimuet Park, and Otter Pond are all in Southampton. However, almost all the Bay Street marina complex at the foot of Main Street is in East Hampton as are the village's high school, the Sag Harbor State Golf Course, and the freed slave community of Eastville.