Democracy and Boundary Commission Cymru

The Democracy and Boundary Commission Cymru (Comisiwn Democratiaeth a Ffiniau Cymru) is a Welsh Government sponsored body, responsible for defining local government boundaries and Senedd constituency boundaries in Wales, also known as Cymru.

The Commission was established originally as the Local Government Boundary Commission for Wales (Comisiwn Ffiniau Llywodraeth Leol i Gymru) keep under review all local government areas in Wales, and the electoral arrangements for the principal areas, and to make such proposals to the Welsh Government as seem desirable in the interests of effective and convenient local government. The name of the commission was changed in 2013 to the Local Democracy and Boundary Commission for Wales (Comisiwn Ffiniau a Democratiaeth Leol Cymru), as a result of the Local Government (Democracy) (Wales) Act 2013. It was renamed again by the Senedd Cymru (Members and Elections) Act 2024 to its current name and given responsibility over reviewing the borders of Senedd constituencies.

Electoral arrangements in six authorities were reviewed after the penultimate round of Welsh local elections in 1999, and the changes were implemented at the elections on 10 June 2004.

In 2002, the commission also reviewed and amended some of the boundaries of the preserved counties of Wales.

In February 2009 the Minister for Local government and Social Justice issued Directions to the commission to begin an Electoral Review across all the 22 local authorities in Wales. His stated aim was to rationalise representation at "... no lower than a ratio of 1 councillor to 1,750 electors ".

As part of electoral reform in the Senedd it will create 16 new constituencies by pairing the 32 Westminster constituencies, these are to be used in the next Senedd election in 2026. Following that election the Commission will conduct a full review of Senedd boundaries and do so every 8 years.