The British Antarctic Territory (BAT) is a sector of Antarctica claimed by the United Kingdom as one of its 14 British Overseas Territories, of which it is by far the largest by area. It comprises the region south of 60°S latitude and between longitudes 20°W and 80°W, forming a wedge shape that extends to the South Pole, overlapped by the Antarctic claims of Argentina and Chile. The claim to the region has been suspended since the Antarctic Treaty came into force in 1961.

The British Overseas Territories (BOTs) are the 14 territories with a constitutional and historical link with the United Kingdom that, while not forming part of the United Kingdom itself, are part of its sovereign territory. The permanently inhabited territories are delegated varying degrees of internal self-governance, with the United Kingdom retaining responsibility for defence, foreign relations and internal security, and ultimate responsibility for good governance. All of the territories are inhabited by civilians, except three that are chiefly or only inhabited by military or scientific personnel. All fourteen have the British monarch as head of state. These UK government responsibilities are assigned to various departments of the Foreign, Commonwealth and Development Office and are subject to change.