unincorporated community in the town (township) of North Hempstead, Nassau county, New York, U.S. It lies on the north shore of Long Island overlooking Manhasset Bay, a summer yachting centre.

The Delaware Indians inhabited the area at the time of settlement. In 1643 they sold the land on which the community was founded to English settlers from Connecticut. The residents were occupied mainly with farming and oyster fishing until the early 20th century.

Savoia Marchetti seaplanes were constructed there after 1929, and Port Washington became an early seaplane base; the Pan American (Pan American World Airways, Inc.) Dixie Clipper left from there for France on June 28, 1939, inaugurating one of the world's first transatlantic passenger airline services. During World War II the Grumman Aircraft Engineering Corporation (Grumman, Leroy Randle) established a major aircraft industry there; high technology industries are now important. Port Washington North is an adjacent residential village, incorporated in 1932. Pop. (1990) 15,387; (2000) 15,215.