Lisburn ( and ) is a city split between County Antrim & County Down, Northern Ireland. The River Lagan denotes the county boundary. Lisburn had a population of 71,465 people in the 2001 Census.

Lisburn was a former United Kingdom Parliament constituency, in Ireland, returning one MP. It was an original constituency represented in Parliament when the Union of Great Britain and Ireland took effect on 1 January, 1801.