Lisburn City Council in the context of "Moira, County Down"

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.

Castlereagh (/ˈkɑːsəlreɪ/ KAH-səl-ray) was a local government district with the status of borough in Northern Ireland. It merged with Lisburn City Council in May 2015 under local government reorganisation in Northern Ireland to become Lisburn and Castlereagh City Council, with a small amount being transferred to Belfast City Council.

It was a mainly urban borough consisting mostly of suburbs of Belfast in the Castlereagh Hills (to the south-east of the city) with a small rural area in the south of the borough. Unusually, it had no natural borough centre. The main centres of population are Carryduff, 6 miles (9.6 km) south of Belfast city centre and Dundonald, 5 miles (8 km) east of it.