This article is about Ailsa Craig, a Scottish island. See also Ailsa Craig, Ontario for the Canadian town.
Ailsa Craig is a small island 2 miles in circumference in the North Channel of the Irish Sea which lies approximately 10 miles west of Girvan in Scotland. It belongs to the administrative district of South Ayrshire, in the ancient parish of Dailly. Rising to 338 metres, this volcanic rock was a haven for Roman Catholics during the Scottish Reformation and is now a bird sanctuary known for its gannets. It is also a source for a particular type of granite (known as "Ailsite") used to make curling stones.
The Ailsa Craig is nicknamed by locals as "Paddy's Milestone", owing to its position approximately halfway between Glasgow and Belfast.
The island is uninhabited, and is home to an automatic lighthouse and a ruined castle.