Yakushima (屋久島) is one of the Ōsumi Islands in Kagoshima Prefecture, Japan. Yakushima is a unique remnant of warm temperate ancient forest and natural World Heritage site since 1993.

Yakushima has been settled since at least the Jōmon period (BCE 縄文時代, Jōmon jidai 14,000–300 BCE). Yakushima contains one of the largest tracts of existing Nansei Islands subtropical evergreen forests, an endangered habitat ecoregion. The only large animals indigenous to the island are red-bottomed macaques (Yakushima macaque) and a variety of sika deer (yakushika). The Japanese raccoon dog is also a common animal, but is not native to the island. Japanese weasels (Mustela itatsi) may also be seen from time to time. The island is a spawning ground for migratory loggerhead turtles, and dolphins are to be found offshore. It has been recognised as an Important Bird Area (IBA) by BirdLife International because they support populations of Japanese wood pigeons, Ryukyu green pigeons and Ryukyu robins.
Yakushima is famous for its lush vegetation and yakusugi (屋久杉) millenarian cedar tree. The best known single example of which is named the Jōmon Sugi (縄文杉), as its age is estimated to date to at least 2300 years ago. In addition, the island lists over 50 varieties of endemic flower, notably rhododendrons, and hundreds of rare endemic Bryophyta, as well as a number of endemic trees. In 1980, an area of 18,958 ha (46,850 acres) was designated a UNESCO Man and the Biosphere Reserve. In 1993, 10 hectares (25 acres) of wetland at Nagata-hama was designated a Ramsar Site. It is the largest nesting ground for the endangered loggerhead sea turtle in the North Pacific.