Java (Indonesian: Jawa) is an island of Indonesia. With a population of 135 million (excluding the 3.6 million on the island of Madura which is administered as part of the provinces of Java), Java is the world's most populous island, and one of the most densely-populated places on the globe. Java is the home of 60 percent of the Indonesian population. The Indonesian capital city, Jakarta, is located on western Java. Much of Indonesian history took place on Java. It was the center of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 40s. Java dominates Indonesia politically, economically and culturally.

Formed mostly as the result of volcanic eruptions, Java is the 13th largest island in the world and the fifth largest island in Indonesia. A chain of volcanic mountains forms an east-west spine along the island. It has three main languages, though Javanese is dominant, and it is the native language of about 60 million people in Indonesia, most of whom live on Java. Most of its residents are bilingual, with Indonesian as their first or second languages. While the majority of the people of Java are Muslim, Java has a diverse mixture of religious beliefs, ethnicities, and cultures.