Carmarthen West and South Pembrokeshire (UK Parliament constituency)

Carmarthen West and South Pembrokeshire (Gorllewin Caerfyrddin a De Sir Benfro) was a constituency of the House of Commons of the Parliament of the United Kingdom. It elected one Member of Parliament (MP) by the first past the post system of election.

The Carmarthen West and South Pembrokeshire Senedd constituency was created with the same boundaries in 1999 (as an Assembly constituency).

The constituency was abolished as part of the 2023 Periodic Review of Westminster constituencies and under the June 2023 final recommendations of the Boundary Commission for Wales. Its wards were split between Caerfyrddin (Carmarthen) and Mid and South Pembrokeshire.

Boundaries
The constituency was created in 1997 from parts of the former marginal seats of Pembroke and Carmarthen. Main population areas in the seat include the towns of Carmarthen, Pembroke Dock, Pembroke and Tenby. Saundersfoot and Dylan Thomas' homestead of Laugharne are also within the constituency.

The constituency included the whole of 22 Carmarthenshire communities (Abernant; Bronwydd; Carmarthen; Cilymaenllwyd; Cynwyl Elfed; Eglwyscummin; Henllanfallteg; Laugharne Township; Llanboidy; Llanddowror; Llangain; Llangynin; Llangynog; Llanpumsaint; Llansteffan; Llanwinio; Meidrim; Newchurch and Merthyr; Pendine; St Clears; Trelech; Whitland), the whole of 24 Pembrokeshire communities (Amroth; Angle; Carew; Cosheston; East Williamston; Hundleton; Jeffreyston; Kilgetty/Begelly; Lampeter Velfrey; Lamphey; Llanddewi Velfrey; Llawhaden; Manorbier; Martletwy; Narberth; Pembroke; Pembroke Dock; Penally; St Florence; St Mary Out Liberty; Saundersfoot; Stackpole and Castlemartin; Templeton; and Tenby), also the eastern part of the Pembrokeshire community of Uzmaston, Boulston and Slebech.

Profile
Carmarthen West and South Pembrokeshire is a marginal seat between the Labour Party and the Conservatives. The Conservatives are very strong around the more rural parts of the seat along with Pembroke, whereas Carmarthen and Pembroke Dock are more inclined to the Labour Party. Plaid Cymru is traditionally stronger in West Carmarthenshire as well as the Tenby area where several local councillors represent the party.

Elections in the 2010s
Of the 65 rejected ballots:
 * 44 were either unmarked or it was uncertain who the vote was for.
 * 14 voted for more than one candidate.
 * 7 had writing or a mark by which the voter could be identified.

Of the 146 rejected ballots:
 * 110 were either unmarked or it was uncertain who the vote was for.
 * 35 voted for more than one candidate.
 * 1 had writing or a mark by which the voter could be identified.