Magheralin (from Irish Machaire Lainne, meaning 'plain of the church') 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.

Its original name was Lann Rónáin Fhinn, "church of Ronan Finn", a saint from the medieval Irish tale Buile Shuibhne (The Madness of Sweeney).

Magheralin has two churches: one Protestant and one Catholic. The Protestant parish has a second church building in Dollingstown. Magheralin's Catholic parish also has two churches: St. Patrick's & St. Ronan's and St. Colman's in Kilwarlin.

There is an old song called "The Ducks of Magheralin". The Ducks of Magheralin is an Irish Polka, with its namesake representing the 'ducks of Magheralin', who were the weavers of the town because they used duck grease to lubricate their looms. In the preface to a well-known version by the Glenfolk Four, the singers insist that the intent of the song is to address the "myth" that the capital of Ireland is Dublin. The first verse is as follows:

Magheralin has two primary schools: Maralin Village Primary School and St. Patrick's Primary School.

During the period of The Troubles (1960s–1998), a number of incidents occurred in the area. On 18 October 1989, Robert Metcalfe, a 40-year-old Protestant civilian, was shot and killed by the Provisional Irish Republican Army while at his home in Drumnabreeze Road, Magheralin. And, in January 1991, Jervis Lynch, a 26-year-old Catholic civilian, was shot and killed by the Ulster Volunteer Force (UVF) while at his home in Acres Road, Magheralin.

St. Michael's GAC is a Gaelic football club with its playing field in Magheralin.

Magheralin also has a football club, Magheralin Village F.C., they play in the Mid Ulster Football League.