Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka and known from the beginning of British colonial rule until 1972 as Ceylon, is an island country in South Asia near south-east India.

Sri Lanka has maritime borders with India to the northwest and the Maldives to the southwest. Its documented history spans 3,000 years, with evidence of pre-historic human settlements dating back to at least 125,000 years. Its geographic location and deep harbours made it of great strategic importance from the time of the ancient Silk Road through to World War II.

A diverse and multicultural country, Sri Lanka is home to many religions, ethnic groups, and languages. In addition to the majority Sinhalese, it is home to large groups of Sri Lankan and Indian Tamils, Moors, Burghers, Malays, Kaffirs and the aboriginal Vedda. Sri Lanka has a rich Buddhist heritage, and the first known Buddhist writings of Sri Lanka, the Pāli Canon, dates back to the Fourth Buddhist council in 29 BC. The country's recent history has been marred by a thirty-year civil war which decisively ended when Sri Lankan military defeated Liberation Tigers of Tamil Eelam in 2009.

Sri Lanka is a republic and a unitary state governed by a presidential system. The legislative capital, Sri Jayawardenepura Kotte, is a suburb of the commercial capital and largest city, Colombo. An important producer of tea, coffee, gemstones, coconuts, rubber, and the native cinnamon, the island contains tropical forests and diverse landscapes with much biodiversity.

Sri Lanka has had a long history of international engagement, as a founding member of the South Asian Association for Regional Cooperation (SAARC), and a member of the United Nations, the Commonwealth of Nations, the G77, and the Non-Aligned Movement. It is the only country in South Asia that is currently rated "high" on the Human Development Index.