Hat Island

Hat Island may refer to:


 * Sombrero, Anguilla (also known as "Hat Island"), the northernmost island of the Lesser Antilles
 * Gedney Island (Washington) (also known as "Hat Island"), an island in Possession Sound, part of Puget Sound, Washington, US
 * Hat Island, Washington, a census-designated place in Snohomish County that is coterminous with Gedney Island
 * Hat Island (Lake Michigan), located in eastern St. James Township, Charlevoix County, Michigan, US
 * Hat Island (Wisconsin), located in the Town of Gibraltar, Door County, Wisconsin, US
 * Putulik formerly Hat Island, in the Kitikmeot Region, Nunavut, Canada
 * Hat Island (Sverdrup Islands), in the Qikiqtaaluk Region, Nunavut, Canada
 * Cocked Hat Island, Nunavut, Canada
 * Vatu Vara, Fiji
 * Eretoka Island, Vanuatu