The Top End is, Cape York Peninsula aside, the northernmost part of Australia. It covers a rather vaguely-defined area of perhaps 400,000 square kilometres bounded by sea on three sides (the Indian Ocean on the west, the Arafura Sea to the north, and the Gulf of Carpentaria to the east), and by the almost waterless semi-arid interior of Australia to the south.

The Top End, though less frequently visited and less well-known overseas than the arid southern part of the Northern Territory (referred to by Australians as the Centre and the largest town of which is Alice Springs), contains nearly all of the Territory's major towns, including Darwin, Katherine, Pine Creek , and Mataranka .

The transition from the lush, steamy tropical environment of the north to the semi-arid mulga scrubs, mallee, and sand dunes of the centre is gradual, and the demarcation line that divides the Top End from the centre is arbitrary.