Which Asian country has Jeju Island as its largest island?

South Korea has Jeju Island as its largest island.

Jeju lies in the Korea Strait, south of the Korean Peninsula, and forms most of Jeju Province. The island covers about 1,826 square kilometres and measures roughly 73 kilometres from east to west. It is the largest island under South Korean administration, larger than other notable South Korean islands such as Ganghwa and Ulleungdo.

Jeju is volcanic in origin. Repeated eruptions built the island over roughly two million years, leaving basalt landscapes, lava tubes, volcanic cones, and Hallasan at its centre. Hallasan reaches about 1,947 metres and is the highest mountain in South Korea. The island’s volcanic features are recognised through the UNESCO World Heritage site Jeju Volcanic Island and Lava Tubes.

A common mix-up is treating Jeju as a separate country or confusing it with Japan’s volcanic islands. Jeju is part of South Korea, though it has a distinct regional culture and a special self-governing provincial status. Its beaches, mild climate, and volcanic scenery make it one of the country’s best-known tourist destinations.