Monmouthshire (Welsh: Sir Fynwy) is a constituency of the House of Commons in the UK Parliament, and was first contested at the 2024 general election, following the 2023 Periodic Review of Westminster constituencies.

[2] Monmouth and Newport East prior to 2024 Somerset was appointed Comptroller of the Household, triggering a by-election.

Somerset resigned by accepting the office of Steward of the Manor of Hempholme, triggering a by-election.

Somerset was appointed Chancellor of the Duchy of Lancaster, triggering a by-election.

Williams resigned by accepting the office of Steward of the Chiltern Hundreds, triggering a by-election