Java, the most populous island of Indonesia. It is bordered on the north by the Java Sea and on the south by the Indian Ocean. Straits separate it from Madura to the northeast, Bali to the east, and Sumatra to the west. Java is about 650 miles (1,050 km) long (east-west) and up to 130 miles (210 km) wide. Its area is 48,842 square miles (126,500 km2).

A great mountain range with many active volcanoes runs along Java's length. Semeru, the highest peak, is 12,060 feet (3,676 m) above sea level. The weather is hot and damp in the lowlands, with no seasonal variation; the highlands are cooler. Java has several important seaports, and major cities are linked by road, rail, and air. Every piece of land fit for cultivation is intensively farmed; rice is grown on terraced hillsides. Other agricultural products are sugar, coffee, tea, rubber, cocoa, corn, cassava, soybeans, and yams. Teak is an important lumber product. Petroleum is the leading mineral resource.

The total population of Java and neighboring Madura in 2000 was 121,352,608. With a population density of nearly 2,485 persons per square mile (960 per km2), Java is perhaps the most crowded area of its size on earth.

Java's largest cities are Jakarta, the national capital (9,373,900); Surabaya (2,801,300); and Bandung (5,919,400).

Java Man, an early form of human, lived on Java more than 600,000 years ago. Hindu traders came to Java after the first century A.D.and established powerful kingdoms. By about 1500 the islanders had been converted to Islam. In 1619 the Dutch founded Batavia (now Jakarta) and gradually spread their rule over the island. The British ruled Java briefly, 1811–16. Following Japanese occupation in World War II, nationalist groups demanded independence from the Netherlands. In 1949 Java became part of the Indonesian Republic, reorganized as the Republic of Indonesia in 1950.