Castlereagh Area B was one of the three district electoral areas in Castlereagh, Northern Ireland which existed from 1973 to 1985.
The district elected eight members to Castlereagh Borough Council, and formed part of the Belfast East constituencies for the Northern Ireland Assembly and UK Parliament.
It was created for the 1973 local elections, and contained the wards of Ballyhanwood, Carrowreagh, Dundonald, Enler, Gilnahirk, Lower Braniel, Tullycarnet and Upper Braniel.
It was abolished for the 1985 local elections and replaced by the Castlereagh East DEA.
1977: 3 x Alliance, 2 x UUP, 2 x DUP, 1 x Independent Unionist 1981: 4 x DUP, 2 x UUP, 2 x Alliance 1977-1981 Change: DUP (two seats) gain from Alliance and Independent Unionist 1973: 4 x UUP, 2 x Alliance, 1 x United Loyalist, 1 x Loyalist Coalition 1977: 3 x Alliance, 2 x UUP, 2 x DUP, 1 x Independent Unionist 1973-1977 Change: DUP (two seats) and Alliance gain from UUP, United Loyalist and Loyalist Coalition 1973: 4 x UUP, 2 x Alliance, 1 x United Loyalist, 1 x Loyalist Coalition