Celebes or Sulawesi, island of eastern Indonesia, one of the larger islands of the Malay Archipelago, situated east of Borneo and west of the Moluccas. It consists mainly of four peninsulas separated by deep gulfs, with two of the peninsulas extending southward and two northeastward. This singular conformation gives the island a coastline of about 5630 km (about 3500 mi). The surface reaches one of its highest elevations in Mount Lompobatang, an extinct volcano in the southern part of the island 2871 m (9419 ft) high. A number of active volcanoes are also found in the eastern end of the northern peninsula, but most of the volcanoes have reached the latent stage. The largest river is the Sadang, which is navigable by small boats.

The climate is tropical, but somewhat modified by the elevation and the proximity of the sea. Among the animals peculiar to the island are the tailless baboon; the babirusa, with upper canines curved backward and nearly touching the forehead; the marsupial cuscus; and the sapiutan or wild cow. The forests include oak, teak, palm, cedar, upas trees, and bamboo. Cloves, nutmeg, spices, tropical fruits, corn, rice, tobacco, and sugar are raised. The coffee crop is not large, but is of superior quality. The minerals include gold, copper, tin, sulfur, salt, and diamonds and other precious stones. Among the chief items of trade are coffee, spices, copra, coconuts, and trepang, an edible sea slug.

The Portuguese first sighted and named the island in 1512, but from about 1607 the Dutch gradually obtained supremacy, although it was not until well into the 19th century that every district was under their control. Under the Dutch the island formed an important province of the Netherlands East Indies, consisting of the Celebes government in the southern part of the island and the Manado residency in the north. The capital of the Celebes government and chief port of the island was Makassar (now Ujung Pandang), situated on Makassar Peninsula, on the Strait of Makassar. The seat of the residency was in Manado, at the end of the Manado Peninsula on the Celebes Sea. During World War II, the Japanese held the island from 1942 until 1945. In 1946 Celebes Island was included in the autonomous state of East Indonesia, a part of the new United States of Indonesia (now Republic of Indonesia). Area, about 189,070 sq km (about 73,000 sq mi), population (1990) 12,522,000.