The Monmouth constituency is one of eight constituencies covering the preserved county of Gwent. It is considered as a rural constituency with many small towns and villages lying within its boundaries. The major towns of the constituency are Abergavenny, Chepstow, Croesyceiliog, Monmouth and Usk; and covers most of current local authority of Monmouthshire, and a small part of the local authority of Torfaen.

The Westminster seat has existed under its current form since 1918 and has been represented by both Conservative and Labour MPs. Since the creation of the Assembly, Monmouth has been represented only by Conservative Assembly Members, the only seat in Wales which can make this claim.

The constituency consists of:

The County of Monmouthshire electoral divisions: Caerwent, Cantref, Castle, Croesonen, Crucorney, Devauden, Dixton with Osbaston, Drybridge, Goytre Fawr, Grofield, Lansdown, Larkfield, Llanbadoc, Llanelly Hill, Llanfoist Fawr, Llangybi Fawr, Llanover, Llantilio Crossenny, Llanwenarth Ultra, Mardy, Mitchel Troy, Overmonnow, Priory, Raglan, St Arvans, St Christopher’s, St Kingsmark, St Mary’s, Shirenewton, Thornwell, Trellech United, Usk andWyesham.

The County Borough of Torfaen electoral divisions: Croesyceiliog North, Croesyceiliog South, Llanyrafon East and Ponthir and Llanyrafon West.