特里斯坦-达库尼亚（Tristan da Cunha；[ˈtrɪstən də ˈkuːnə]）是南大西洋的一个群岛，是英国海外领地圣赫勒拿、阿森松和特里斯坦-达库尼亚的一部分。它是全世界最偏远而有人居住的离岛，距离南非2816公里，距离南美洲3360公里。

特里斯坦-达库尼亚群岛包括主岛特里斯坦-达库尼亚岛（98平方公里）和几个无人岛：伊纳克瑟布尔岛（Inaccessible Island）和南丁格尔群岛（Nightingale Islands）。戈夫岛（Gough Island）在主岛东南面395公里。

Tristan da Cunha /ˈtrɪstən də ˈkuːnjə/, colloquially Tristan, is both a remote group of volcanic islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying 2,000 kilometres (1,200 mi) from the nearest inhabited land, Saint Helena, 2,400 kilometres (1,500 mi) from the nearest continental land, South Africa, and 3,360 kilometres (2,090 mi) from South America. The territory consists of the main island, also named Tristan da Cunha, which has a north–south length of 11.27 kilometres (7.00 mi) and has an area of 98 square kilometres (38 sq mi), along with the smaller, uninhabited Nightingale Islands and the wildlife reserves of Inaccessible and Gough Islands.