Indonesia (Indonesia: Indonesia), officially the. The Republic of Indonesia (Indonesian: Republik Indonesia), is the largest island in the world. Located between Indochina and Australia. Between the Indian Ocean and the Pacific. Borders with Malaysia on Borneo or Kalimantan. (Kalimantan), Papua New Guinea, or e-learning (Irian) and Timor - Leste on the island of Timor (Timor).