Lagan Valley (Irish: Gleann an Lagáin, Ulster Scots: Glen Lagan) is a constituency in the Northern Ireland Assembly.

Since 1998, it has elected members to the current Assembly.

For Assembly elections prior to 1996, the constituency was largely part of the South Antrim and North Down constituencies.

Since 1997, it has shared boundaries with the Lagan Valley UK Parliament constituency.

Successful candidates are shown in bold.