Kangaroo Island, small island, South Australia, S Australia, at the entrance to Gulf St. Vincent. It is 90 mi (145 km) long and 34 mi (55 km) wide. The chief products are barley, sheep, salt, gypsum, and eucalyptus oil. At its west end is Flinders Chase, a large reservation for native flora and fauna. There are many summer resorts. Kingscote (1991 pop. 1,443) is the principal settlement.