Which country is the largest island nation by area?

Indonesia is the largest island nation in the world by area.

Indonesia is an archipelagic country spread between the Indian and Pacific oceans, with territory extending roughly 5,120 kilometres from west to east. Its land area is about 1.9 million square kilometres, including the islands and inland seas within its borders. The country is commonly described as having more than 17,000 islands, although counts vary because small, tidal and uninhabited islands are surveyed differently.

Its five principal islands or island regions are Sumatra, Java, Sulawesi, Borneo and New Guinea. Several are shared with other countries: Indonesia controls Kalimantan on Borneo and western New Guinea, while Malaysia, Brunei and Papua New Guinea occupy the remaining portions.

The wording matters. Greenland is the world’s largest island, but it is an autonomous territory within the Kingdom of Denmark rather than a sovereign island nation. Madagascar, Japan and Papua New Guinea are all island countries, yet each has a smaller total area. Indonesia’s unusually large territory also gives it major maritime importance, linking the Indian and Pacific oceanic trade routes.