List of island counties of the United States

This is a list of counties and county-equivalents of the United States situated entirely or predominantly on islands. The United States of America is composed of 50 states, which are in turn divided into counties or county-equivalents (parishes, boroughs, independent cities, or census divisions). However, only a small fraction of those are situated entirely on islands. This list does not include county-equivalents in U.S. territories or commonwealths, such as Puerto Rico.

State	Body of water	County	Seat	Population (2015)	Island(s)
Alaska	Pacific Ocean	Aleutians West[1]	None[1]	5,702[2]	Aleutian Islands, Pribilof Islands
	Gulf of Alaska	Kodiak Island	Kodiak	13,889	Afognak Island, Chirikof Island, Kodiak Island and surrounding islands, Semidi Islands Small part situated on the mainland.
		Sitka	Sitka	8,863	Baranof Island, Chichagof Island Consolidated city-county
		Prince of Wales–Hyder	None[1]	6,341	Annette Island, Prince of Wales Island and surrounding islands The community of Hyder is an exclave situated on the mainland.
Florida	Gulf of Mexico	Monroe	Key West	77,482	Florida Keys While most of the county is situated on the mainland, almost all of the population lives on islands.
Hawaii	Pacific Ocean	Hawaii	Hilo	196,428	Island of Hawaii Hawaii is the only state situated entirely on islands.
		Honolulu	Honolulu	998,714	Oahu, Northwestern Hawaiian Islands Consolidated city-county
		Kalawao	None[3]	89	Molokai
		Kauai	Lihue	71,735	Kauai, Niihau, Kaula, Lehua
		Maui	Wailuku	164,637	Maui, Molokai, Lanai, Kahoolawe, Molokini
Massachusetts	Atlantic Ocean	Dukes	Edgartown	17,356	Martha's Vineyard, Elizabeth Islands, Nomans Land
		Nantucket	Nantucket	10,172	Nantucket Island, Muskeget Island, Tuckernuck Island Consolidated city-county
Michigan	Lake Superior	Keweenaw	Eagle River	2,168	Keweenaw Peninsula, Isle Royale, Manitou Island The Keweenaw Waterway, which is partly natural, partly manmade and was created in the 1960s, divides the Keweenaw Peninsula in half and forms an island from the northern part. Keweenaw County is situated entirely on this "island".
New York	Atlantic Ocean, Long Island Sound	Kings	None[4]	2,636,735	Long Island and neighboring small islands Conterminous with Brooklyn, a borough of New York City
		Nassau	Mineola	1,361,350	Long Island, Barnum Island, Jones Beach Island, Long Beach Barrier Island, other neighboring small islands
	Hudson River, East River	New York	None[4]	1,644,518	Manhattan Island, Ellis Island Governors Island, Liberty Island, Randalls and Wards Islands, Roosevelt Island A small part (Marble Hill) is situated on the mainland. Conterminous with Manhattan, a borough of New York City.
	Atlantic Ocean, Long Island Sound	Queens	None[4]	2,339,150	Long Island and neighboring small islands Conterminous with Queens, a borough of New York City
	Lower New York Bay, Arthur Kill	Richmond	None[4]	474,558	Staten Island, Prall's Island, other small surrounding islands Conterminous with Staten Island, a borough of New York City
	Atlantic Ocean, Long Island Sound	Suffolk	Riverhead	1,501,587	Long Island, Fire Island, Gardiners Island, Robins Island, Shelter Island, and other neighboring small islands
Rhode Island	Narragansett Bay	Newport	Newport	82,243	Aquidneck Island, Conanicut Island, Prudence Island, surrounding small islands Part of the county is situated on the mainland. The majority of the population resides on Aquidneck Island.
Vermont	Lake Champlain	Grand Isle	North Hero	6,861	Grand Isle, Isle La Motte, North Hero Island, numerous smaller islands A part of the county is situated on the mainland.
Washington	Puget Sound	Island	Coupeville	80,593	Camano Island, Whidbey Island, seven smaller islands
		San Juan	Fridar Harbor	16,252	San Juan Islands

References

1. Alaska is composed of nineteen organized boroughs and the large Unorganized Borough, which for statistical purposes is divided into ten census areas. The census areas have no seat and no county-level government.
2. "County Totals Dataset: Population, Population Change and Estimated Components of Population Change: April 1, 2010 to July 1, 2015". Retrieved July 2, 2016.
3. Administered by Hawaii Department of Health. Largest town is Kalaupapa, where most of the county's residents reside.
4. Borough of New York City, and as such has no county seat.

External links

• United States Government
  • United States Census Bureau
  • United States Office of Management and Budget