Monmouth (Welsh: Sir Fynwy) is a county constituency of the House of Commons of the Parliament of the United Kingdom (at Westminster). It elects one Member of Parliament (MP) by the first past the post of election. The constituency was created for the 1918 general election. Since 2005 the MP has been David Davies of the Conservative Party.
The Monmouth Welsh Assembly constituency, created in 1999, has normally the same boundaries as the Westminster constituency.
The current MP is the Conservative David Davies, elected in 2005 and a former member for the Welsh Assembly seat of the same name. To avoid confusion with the Yorkshire Conservative David Davis, he is named in Hansard as "David T.C. Davies".
The constituency is one of eight covering the preserved county of Gwent. The other seven are Blaenau Gwent, Caerphilly, Islwyn, Merthyr Tydfil and Rhymney, Newport East, Newport West and Torfaen. Merthyr Tydfil and Rhymney, however, straddles the boundary with the preserved county of Mid Glamorgan. It covers most of current local authority of Monmouthshire, with the main towns being Chepstow and Monmouth.
For the 2010 general election, there were no changes to the boundaries of the Monmouth constituency stemming from the Fifth Review of the Boundary Commission for Wales. Likewise there were no boundary changes in 1997.
As first used in the 1918 general election, the constituency was a creation of the Representation of the People Act 1918 as one of six constituencies covering the county of Monmouth. Prior to the 1918 election the county had been covered, nominally, by the county constituencies of Northern Monmouthshire, Southern Monmouthshire, and Western Monmouthshire, and the Monmouth Boroughs borough constituency. By 1918, however, administrative county boundaries were out of alignment with constituency boundaries. The new constituency boundaries took account of the new local government boundaries.