Rathlin Island is an island and civil parish off the coast of County Antrim in Northern Ireland. It is Northern Ireland's northernmost point. As of the 2021 Census there are 141 people living on the island.

County Antrim is one of the six counties of Northern Ireland, located within the historic province of Ulster. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 3,086 square kilometres (1,192 sq mi) and has a population of 651,321, as of the 2021 census. County Antrim has a population density of 211 people per square kilometre or 546 people per square mile. It is also one of the thirty-two traditional counties of Ireland.