More than 700 living languages are spoken in Indonesia. This figure indicates that Indonesia has about 10% of the world's languages, establishing its reputation as the second most linguistically diverse nation in the world after Papua New Guinea. Most languages belong to the Austronesian language family, while there are over 270 Papuan languages spoken in eastern Indonesia. The language most widely spoken as a native language is Javanese.

Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea. Indonesia is the world's largest archipelagic state and the 14th-largest country by area, at 1,904,569 square kilometres. With over 279 million people, Indonesia is the world's fourth-most-populous country and the most populous Muslim-majority country. Java, the world's most populous island, is home to more than half of the country's population.