This is a list of selected Australian islands grouped by State or Territory. Australia has 8,222 islands within its maritime borders. The area of the continent of Australia is 6,560,000 square kilometres (2,530,000 sq mi). The islands larger than 1,000 square kilometres (390 sq mi) are:1  Mainland Tasmania (Tas) 64,519 square kilometres (24,911 sq mi);2  Melville Island, Northern Territory (NT), 5,786 square kilometres (2,234 sq mi); 3  Kangaroo Island, South Australia (SA), 4,416 square kilometres (1,705 sq mi); Bird Island, located near Budgewoi, 1.4 kilometres (0.87 mi) east of the Central Coast. 2  Boondelbah Island, at the mouth of Port Stephens. 3  Broughton Island (New South Wales) , located north of Port Stephens.