Lý Sơn (listenⓘ), previously known as Cù Lao Ré,[2] is an insular district of Quảng Ngãi province, lying off the South Central Coast of Vietnam.

The main island, Lý Sơn (Cù Lao Ré) has three prominent craters, the largest of which is Mount Thoi Loi (Thới Lới).

[6] During the United States involvement in the Vietnam War, Lý Sơn was the site of a U.S. Navy radar installation that was used to track shipping along the Vietnamese coast.

Lý Sơn is a major offshore fishing center with an output of 29,000 tonnes worth VND241.2 billion ($11.4 million) in 2012, accounting for almost one fourth of Quảng Ngãi's total.

[7] Lý Sơn is also known throughout Vietnam for its production of a special variety of garlic,[8] although coastal sand mining to support its extensive cultivation has led to significant erosion.