The South Fork of Suffolk County, New York is a peninsula in the southeastern section of the county on the South Shore of Long Island. The South Fork includes most of the Hamptons. The shorter, more northerly peninsula is known as the North Fork.

Suffolk County is the easternmost county in the U.S. state of New York. It is bordered to its west by Nassau County, to its east by Gardiners Bay and the Atlantic Ocean, to its north by Long Island Sound, and to its south by Great South Bay. The county is part of the Long Island region of the state, of which it comprises the eastern two-thirds.