Gardiner's Island is a small island in the Town of East Hampton, New York, in Eastern Suffolk County. It is located in Gardiner's Bay between the two peninsulas at the east end of Long Island. It is 6 miles (9.7 km) long, 3 miles (4.8 km) wide and has 27 miles (43 km) of coastline.

The Town of East Hampton is located in southeastern Suffolk County, New York, at the eastern end of the South Shore of Long Island. It is the easternmost town in the state of New York. At the time of the 2020 United States census, it had a total population of 28,385.