(rāünyôN'), island and overseas department of France (2015 est. pop. 863,000), c.970 sq mi (2,510 sq km), one of the Mascarene Islands, in the Indian Ocean c.430 mi (690 km) E of Madagascar. Saint-Denis (the capital) and Le Port (the leading port) are the chief cities.
The island is composed mainly of one active and several extinct volcanoes; its highest point is Le Piton des Neiges (10,069 ft/3,069 m). Le Piton de la Fournaise in S Réunion is one of the earth's most active volcanoes. Settlement and cultivation are concentrated in the coastal lowlands. Most of the inhabitants are Roman Catholic and speak a creole patois. Since the 19th cent. sugar has been by far the island's chief product and export. Molasses, vanilla, tobacco, tropical fruits, and rum are also produced.
Réunion was known to the Arabs and was visited by the Portuguese in the early 16th cent. The island was uninhabited until settled by the French c.1642; its present mixed population is descended from the French settlers and their East African, South Asian, and Indochinese slaves (after 1848, when slavery was abolished, indentured laborers). At first a penal colony, Réunion became a post of the French East India Company in 1665. In the 18th cent. the island was an exporter of coffee. From 1810 to 1814 Réunion was held by Great Britain. After 1815, when coffee no longer could be produced competitively, sugarcane became the main crop. In 1947 the status of Réunion was changed from a colony to an overseas department. In the 1980s and 90s, the citizens of Réunion sought greater political autonomy and better wages and working conditions.