Much of the Port Washington area was settled by colonists in 1644, after they purchased land from the people of the Matinecock Nation.

[2][3] In the 1870s, Port Washington became an important sand-mining town; it had the largest sandbank east of the Mississippi River and easy barge access to Manhattan.

[6] This plan ultimately failed when the bill was killed after Baxter Estates, Flower Hill, and Manorhaven incorporated themselves as villages in order to retain home rule over their respective areas.

[6] The Port Washington Post Office – commissioned by the United States Government as part of the New Deal – opened in 1935.

[7][8] In the late 1930s, prior to the opening of the Marine Air Terminal at LaGuardia Airport, Port Washington was Pan-American World Airways' New York base for their Yankee Clipper Boeing B-314 flying boats; the waters of Manhasset Bay were ideal for flying boat operations.

[13][14] According to the United States Environmental Protection Agency and the United States Geological Survey, the highest point in Port Washington is Beacon Hill, at an elevation of roughly 270 feet (82 m), and the lowest point is Hempstead Harbor and Manhasset Bay, which are at sea level.

[17]According to the United States Department of Agriculture (USDA), Port Washington is located within hardiness zone 7b.

Entertainment One, NPD Group, Pall, and Systemax, as well as a Hilton Garden Inn are located in that industrial complex.

[11] It is in North Hempstead Town Council's 6th district, which as of January 2025 is represented by Mariann Dalimonte (D–Port Washington).

[27] Port Washington is in the Nassau County Legislature's 11th legislative district, which as of January 2025 is represented by Delia DiRiggi-Whitton (D–Glen Cove).

[11][28] Port Washington is in New York's 7th State Senate district, which as of January 2025 is represented by Jack M. Martins (R–Old Westbury).

[11][29] Port Washington is in New York's 16th State Assembly district, which as of January 2025 is represented by Daniel J. Norber (R–Great Neck).

[11][30][31] Port Washington is in New York's 3rd congressional district, which as of January 2025 is represented in the United States Congress by Thomas R. Suozzi (D–Glen Cove).

[11][32] Like the rest of New York, Port Washington is represented in the United States Senate by Charles Schumer (D) and Kirsten Gillibrand (D).

[11][50] Additionally, a small portion of the hamlet's southeastern corner is within the boundaries of the Roslyn Union Free School District.

[11][64] The Thomas Dodge Homestead, Main Street School, and the Monfort Cemetery are listed on the National Register of Historic Places.