Kalgin Island (Dena'ina:ÃÂ Qelghin) is an island in Cook Inlet of the Gulf of Alaska, southwest of the city of Kenai, Alaska, United States. It is part of the Kenai Peninsula Borough and has a land area of 58.722 km<sup>2</sup> (22.673 sq mi), is long and reported an official resident population of one person as of the 2000 census.