Ireland (Éire; Ulster Scots: Airlann) is the third largest island in Europe, and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain. Politically, the state Ireland (described as the Republic of Ireland in cases of ambiguity) covers five-sixths of the island, with Northern Ireland (NI), part of the United Kingdom, covering the remainder in the north-east.

The population of the island is slightly over six million (2007), with 4.34 million in the Republic (1.7 million in Greater Dublin ) and an estimated 1.75 million in Northern Ireland (0.6 million in Greater Belfast ). This is a significant increase from a modern historical low in the 1960s, but still much lower than the peak population of over 8 million in the early 19th century, prior to the Irish potato famine.

The name Ireland derives from the name Ériu (in modern Irish, Éire) with the addition of the Germanic word land. Most other western European names for Ireland derive from the same source, such as French Irlande, Spanish, Italian and Portuguese Irlanda, German Irland and the Dutch Ierland.