The Senedd constituencies and electoral regions (Welsh: Etholaethau a Rhanbarthau etholiadol Senedd Cymru) are the electoral districts used to elect Members of the Senedd (MS; Welsh: Aelodau'r Senedd or AS) to the Senedd (Welsh Parliament; Welsh: Senedd Cymru), and have been used in some form since the first election of the then National Assembly for Wales in 1999. New boundaries were introduced for the 2007 elections and currently consist of forty constituencies and five regions. The five electoral regions are: Mid and West Wales, North Wales, South Wales Central, South Wales East, and South Wales West, with the forty constituencies listed below. Voting last took place in all districts in the 2021 Senedd election, and are not used for local government.