The Falklands War (Spanish: Guerra de Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial dependency, South Georgia and the South Sandwich Islands. The conflict began on 2 April 1982, when Argentina invaded and occupied the Falkland Islands, followed by the invasion of South Georgia the next day. On 5 April, the British government dispatched a naval task force to engage the Argentine Navy and Air Force before making an amphibious assault on the islands. The conflict lasted 74 days and ended with an Argentine surrender on 14 June, returning the islands to British control. In total, 649 Argentine military personnel, 255 British military personnel, and three Falkland Islanders were killed during the hostilities.

The conflict was a major episode in the protracted dispute over the territories' sovereignty. Argentina asserted (and maintains) that the islands are Argentine territory, and the Argentine government thus described its military action as the reclamation of its own territory. The British government regarded the action as an invasion of a territory that had been a Crown colony since 1841. Falkland Islanders, who have inhabited the islands since the early 19th century, are predominantly descendants of British settlers, and strongly favour British sovereignty. Neither state officially declared war, although both governments declared the islands a war zone.