Antrim and Newtownabbey, district, east-central Northern Ireland. It is bounded to the north and northeast by the Mid and East Antrim district, to the east by Belfast Lough, to the southeast by Belfast City, to the south by Lisburn and Castlereagh City district, to the west by Lough Neagh, and to the northwest by the Mid Ulster district. The district’s administrative body, the Antrim and Newtownabbey Borough Council, meets in Newtownabbey. Antrim and Newtownabbey was created in 2015 by the merger of the districts of Antrim and Newtownabbey. Pop. (2011) 138,567.