Buton (also Butung, Boeton or Button) is an island in Indonesia located off the southeast peninsula of Sulawesi. It covers roughly 4,727 square kilometers in area, or about the size of Madura; it is the 129th largest island in the world and Indonesia's 19th largest in area.

In the precolonial era, the island, then usually known as Butung, was within the sphere of influence of Ternate. Especially in the sixteenth century, Buton served as an important secondary regional center within the Ternaten empire, controlling regional trade and collecting tribute to be sent to Ternate.

The Sultanate of Buton ruled over the island from the 14th until the 20th century.

Sultan Murhum, the first Islamic monarch on the island, is remembered in the name of the island's major harbor, Murhum Harbor, in Baubau.

Its largest town is Baubau, where the Wolio and Cia-Cia languages are spoken. Major nearby islands include Wawonii (to the north), Muna and Kabaena (to the west) and Siumpu (to the southwest). The Tukangbesi Islands lie just to the east where Tukang Besi is spoken, and is separated by the Gulf of Kolowana Watabo (Teluk Kolowana Watabo).

Batuatas Island is to the south. Also the Bouton Passage (as it was known in the pre-Independence era) was an important inter-island navigational location of the northern Flores Sea.

The island is largely covered by rainforest and is known for its wildlife. It is one of only two habitats of the anoa, a type of buffalo.

The languages spoken on Buton include Wolio, Cia-Cia, various dialects of Muna, Tukang Besi, Kumbewaha, Lasalimu, Kamaru, Pancana, Busoa, Taloki, Kulisusu and Kioko. The Indonesian language, the national language of Indonesia, is also widely used and taught in schools.