Aru Islands, Indonesian Kepulauan Aru, Dutch Aroe Eilanden, easternmost island group of the Moluccas, eastern Indonesia, in the Arafura Sea. Administratively they form part of Maluku province. The group extends north-south about 110 miles (180 km) and some 50 miles (80 km) east-west and consists largely of six main islands (Warilau, Kola, Wokam, Kobroor, Maikoor, and Trangan) separated by five narrow channels. About 85 smaller islands bring the group’s total area to 3,306 square miles (8,563 square km). Dobo, the main town, on small Wamar Island, is the site of the principal harbour and a minor airport. All the islands are low, covered with dense forest, and edged by swampy coastal areas. Vegetation includes screw pines, palm trees, kanari (Java almond), and tree ferns. Trangan has grassy plains. Fauna is Papuan with strong Australian affinities; marsupials are the dominant mammals.
The inhabitants are of mixed Papuan and Malay ancestry and adhere to traditional animist religions. Some Muslims and Christians inhabit the western islands, where the villages are coastal and nestle among clumps of trees. In the eastern islands the villages stand on high rocks. Houses are entered by a trapdoor in the middle of the floor. Crops include sago, rice, corn (maize), sugar, tobacco, and coconuts. Collecting trepang, pearls, mother-of-pearl, and tortoiseshells provides the islanders’ main income.
Visited in 1606 by the Dutch, the Aru Islands were occupied by the Japanese in 1942. After World War II they reverted to the Netherlands, and they became part of Indonesia in 1949.