The Belfast metropolitan area, also known as Greater Belfast, is a grouping of council areas which include commuter towns and overspill from Belfast, Northern Ireland, with a population of 671,559 in 2011 and 704,406 in 2021. The area combines the Belfast, Lisburn, Newtownabbey, North Down, Castlereagh and Carrickfergus districts from before the local government reorganization of 2014. This equates to 37.1% of Northern Ireland's population.