Blaenau Gwent (pronounced / /, Welsh: [ˈbləɨ.naɨ]) is a county borough in Wales, sharing its name with a parliamentary constituency. It borders the unitary authority areas of Monmouthshire and Torfaen to the east, Caerphilly to the west and Powys to the north. Its main towns are Abertillery, Brynmawr, Ebbw Vale and Tredegar. Its highest point is Coity Mountain at 1,896 feet (578 m).
The borough was formed in 1974 as a local government district of Gwent. It was a merger of the Monmouthshire urban districts of Abertillery, Ebbw Vale, Nantyglo and Blaina and Tredegar, along with Brynmawr urban district and the parish of Llanelly in Brecknockshire.
It was reconstituted in 1996 as a county borough, and at the same time the area of Llanelly was transferred to the reconstituted Monmouthshire. The area is now governed by Blaenau Gwent County Borough Council, which is a principal council.
Blaenau Gwent hit the headlines at the 2005 UK General Election when an independent candidate, Peter Law, won the Westminster seat. He had resigned from the Labour Party after an internal party row following the retirement of incumbent MP Llew Smith, and defeated the official Labour candidate, Maggie Jones, by a margin of 9,121 votes. The seat had previously been held by Aneurin Bevan and Michael Foot, and was considered one of Labour's safest. Law died on 25 April 2006 and in the by-election, a former supporter of his, Dai Davies won, running as an independent candidate. Peter Law's widow, Trish Law, won his former Welsh Assembly seat, also running as an independent candidate. In 2007 she retained her seat. Dai Davies held the Westminster seat for the People's Voice from 2006 - 2010 when he lost his seat in a huge majority to Labour's Nick Smith of 10,516 votes. Alun Davies recaptured the seat for Labour at the Assembly elections in 2011 and then Labour won a landslide victory in the 2012 local elections taking 33 seats out of 42. Plaid Cymru nearly won the seat in the 2016 Assembly election, and Labour lost the council in the 2017 local elections.