Jeju-do (transliterated Korean for Jeju Province, short form of Jeju Special Self-Governing Province) is the only special self-governing province of South Korea, situated on and coterminous with the country's largest island. Jeju-do lies in the Korea Strait, southwest of Jeollanam-do Province, of which it was a part before it became a separate province in 1946. Its capital is the city of Jeju.

The island contains the Natural World Heritage Site entitled Jeju Volcanic Island and Lava Tubes.