The Largest Islands in the Indian Ocean

Madagascar sits off the eastern coast of southern Africa.
Madagascar sits off the eastern coast of southern Africa.

The Indian Ocean is the third largest of the world's oceans with an area of about 27,240,000 square miles. It accounts for 20% of the earth's surface water. The Indian Ocean borders Australia on the east, Africa on the west, Asia on the north, and Antarctica on the south. The islands of the Indian Ocean are not as large as those of the Pacific, but they are equally popular. The islands include Reunion, Madagascar, Sri Lanka, Zanzibar, Comoros, and Mauritius. The following are the largest islands in the Indian Ocean.

​The Largest Islands in the Indian Ocean


Madagascar is the largest island with an area of about 226,658 square miles. It is the fourth largest in the world after Greenland, New Guinea, and Borneo. Madagascar lies 250 miles off the eastern coast of southern Africa. It is a sovereign state of approximately 26 million. Madagascar is a member of the United Nations and the African Union. France colonized it until June 26, 1960, when it gained independence. Despite being a popular tourist attraction, Madagascar is among the poor states of the world.

Sri Lanka

Sri Lanka is an independent state in South Asia. It is an island state covering an area of approximately 25,200 square miles making it the second largest island in the ocean and the 25th largest in the world. Sri Lanka is culturally and historically linked to India although it is separated by the Palk Strait and the Gulf of Mannar. The country gained independence from the British on February 4, 1948. It is an essential port for goods to South Asia because of its strategic location and deep harbors. Sri Lanka is a major producer of Ceylon tea, rubber, and cinnamon.

Grande Terre

Grande Terre is the primary and largest island of New Caledonia. The island was discovered in 1774 by James Cook who named it “New Caledonia." Eventually, the name was adopted as the name of all the surrounding islands. It is the third largest island in the ocean and the 53rd largest in the world with an area of approximately 6,428 square miles. Nouméa is the largest settlement in the island and capital of New Caledonia. Grande Terre is narrow but elongated with a length of 250 miles and a maximum width of 40 miles.

Sovereign Island states of the Indian Ocean

Both Madagascar and Sri Lanka are sovereign states with functional governments, but Grand Terre is a territory of New Caledonia, an overseas department of France. Reunion is another French Territory while Zanzibar is part of Tanzania. Other sovereign states include Comoros and Mauritius.

The Largest Islands in the Indian Ocean

RankIsland Area (sq km)
2Sri Lanka65,610
3Grande Terre6,675

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