Magheralin is a village and civil parish in County Down, Northern Ireland. It is on the main A3 road between Moira and Lurgan, beside the River Lagan. It had a population of 2,041 people in the 2021 Census. The civil parish of Magheralin covers an area of County Down.

County Down is one of the six counties of Northern Ireland, one of the nine counties of Ulster and one of the traditional thirty-two counties of Ireland. It covers an area of 961 sq mi (2,490 km2) and has a population of 552,261. It borders County Antrim to the north, the Irish Sea to the east, County Armagh to the west, and County Louth across Carlingford Lough to the southwest.