Northwest Harbor is a hamlet and census-designated place (CDP) in the Town of East Hampton, Suffolk County, New York, United States.

It is also applied to Northwest Landing at Northwest Creek (a saltwater outlet from the inlet to the harbor) which was the first port for East Hampton and which became a major whaling port in the late 17th and early 18th centuries[3] until it was replaced by Sag Harbor two miles to the west of the landing, where the water was deeper.

During the American Revolution it was the site of two conflicts, including Meigs Raid in which Americans burned Sag Harbor and captured 90 British soldiers and an incident in which Isaac Van Scoy killed a British soldier with a pitchfork.

During the Great Hurricane of 1938 sand all but enclosed the harbor at its mouth at the Cedar Point Lighthouse, leaving only a narrow channel into Gardiners Bay.

In January 2007 Northwest Landing made national news in efforts to save several common dolphins that had swum up the creek.