# List of parliamentary constituencies in Dyfed

Five constituencies cover Dyfed, also used for elections to the Senedd. The current boundaries have been effective since the 2007 Welsh Assembly election and the 2010 United Kingdom general election.
Dyfed is one of the eight preserved counties of Wales, consisting of the principal areas of Pembrokeshire, Carmarthenshire and Ceredigion. These principal areas are also known as counties.
For Senedd elections, constituencies are grouped into additional member electoral regions.

## Westminster boundaries
### From 2010

| Constituency | Boundaries |
| 1. Carmarthen East and Dinefwr CC (Westminster) | Parliamentary constituencies in Dyfed 2010 |
| 2. Carmarthen West and South Pembrokeshire CC (Westminster) | Parliamentary constituencies in Dyfed 2010 |
| 3. Ceredigion CC (Westminster) | Parliamentary constituencies in Dyfed 2010 |
| 4. Llanelli CC (Westminster) | Parliamentary constituencies in Dyfed 2010 |
| 5. Preseli Pembrokeshire CC (Westminster) | Parliamentary constituencies in Dyfed 2010 |
Conservative †  Labour ‡  Plaid Cymru ₪
| Constituency | Electorate | Majority | Member of Parliament | Nearest opposition | Map reference above |
| Carmarthen East and Dinefwr CC (Westminster) | 57,407 | 1,809 | Jonathan Edwards ₪ | Havard Hughes † | 1 |
| Carmarthen West and South Pembrokeshire CC (Westminster) | 58,629 | 7,745 | Simon Hart † | Marc Tierney ‡ | 2 |
| Ceredigion CC (Westminster) | 56,250 | 6,329 | Ben Lake ₪ | Amanda Jenner † | 3 |
| Llanelli CC (Westminster) | 60,513 | 4,670 | Nia Griffith ‡ | Tamara Reay † | 4 |
| Preseli Pembrokeshire CC (Westminster) | 59,586 | 5,062 | Stephen Crabb † | Philippa Thompson ‡ | 5 |

### 1997 to 2010

| Constituency | Boundaries |
| 1. Carmarthen East and Dinefwr CC (Westminster) | Parliamentary constituencies in Dyfed pre-2010 |
| 2. Carmarthen West and South Pembrokeshire CC (Westminster) | Parliamentary constituencies in Dyfed pre-2010 |
| 3. Ceredigion CC (Westminster) | Parliamentary constituencies in Dyfed pre-2010 |
| 4. Llanelli CC (Westminster) | Parliamentary constituencies in Dyfed pre-2010 |
| 5. Preseli Pembrokeshire CC (Westminster) | Parliamentary constituencies in Dyfed pre-2010 |

## Proposed boundary changes

The Boundary Commission for Wales submitted their final proposals in respect of the Sixth Periodic Review of Westminster Constituencies (the 2018 review) in September 2018. Although the proposals were immediately laid before Parliament they were not brought forward by the Government for approval. Accordingly, they did not come into effect for the 2019 election which took place on 12 December 2019, and which was contested using the constituency boundaries in place since 2010.
Under the terms of the Parliamentary Voting System and Constituencies Act 2011, the Sixth Review was based on reducing the total number of MPs from 650 to 600 and a strict electoral parity requirement that the electorate of all constituencies should be within a range of 5% either side of the electoral quota.
On 24 March 2020, the Minister of State for the Cabinet Office, Chloe Smith, issued a written statement to Parliament setting out the Government's thinking with regard to parliamentary boundaries. They propose to bring forward primary legislation to remove the statutory obligation to implement the 2018 Boundary Review recommendations, as well as set the framework for future boundary reviews in time for the next review which is due to begin in early 2021 and report no later than October 2023. It is proposed that the number of constituencies now remains at the current level of 650, rather than being reduced to 600, while retaining the requirement that the electorate should be no more than +/- 5% from the electoral quota.

## Senedd boundaries
### From 2007

| Constituency | Senedd region | Constituency boundaries |
| 1. Carmarthen East and Dinefwr CC (Senedd) | Mid and West Wales | Assembly constituencies in Dyfed 2007 |
| 2. Carmarthen West and South Pembrokeshire CC (Senedd) | Mid and West Wales | Assembly constituencies in Dyfed 2007 |
| 3. Ceredigion CC (Senedd) | Mid and West Wales | Assembly constituencies in Dyfed 2007 |
| 4. Llanelli CC (Senedd) | Mid and West Wales | Assembly constituencies in Dyfed 2007 |
| 5. Preseli Pembrokeshire CC (Senedd) | Mid and West Wales | Assembly constituencies in Dyfed 2007 |
The Mid and West Wales region also includes two Powys constituencies and one Gwynedd constituency.

### 1999 to 2007

| Constituency | Assembly region | Constituency boundaries |
| 1. Carmarthen East and Dinefwr CC (Assembly) | Mid and West Wales | Assembly constituencies in Dyfed pre-2007 |
| 2. Carmarthen West and South Pembrokeshire CC (Assembly) | Mid and West Wales | Assembly constituencies in Dyfed pre-2007 |
| 3. Ceredigion CC (Assembly) | Mid and West Wales | Assembly constituencies in Dyfed pre-2007 |
| 4. Llanelli CC (Assembly) | Mid and West Wales | Assembly constituencies in Dyfed pre-2007 |
| 5. Preseli Pembrokeshire CC (Assembly) | Mid and West Wales | Assembly constituencies in Dyfed pre-2007 |

## Historical representation by party

A cell marked → (with a different colour background to the preceding cell) indicates that the previous MP continued to sit under a new party name.

### 1832 to 1859

Conservative  Peelite  Radical  Whig
| Constituency | 1832 | 1835 | 1837 | 38 | 1841 | 42 | 46 | 1847 | 49 | 52 | 1852 | 54 | 55 | 1857 | 57 |
| Cardigan Boroughs | P. Pryse | P. Pryse | P. Pryse | P. Pryse | P. Pryse | P. Pryse | P. Pryse | P. Pryse | Loveden | Loveden | Loveden | Loveden | J. Davies | E. Pryse | E. Pryse |
| Cardiganshire | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | W. E. Powell | Vaughan | Vaughan | Vaughan | Vaughan |
| Haverfordwest Bors | R. Philipps | W. Scourfield | R. Philipps | R. Philipps | R. Philipps | R. Philipps | R. Philipps | Evans | Evans | Evans | J. Scourfield | J. Scourfield | J. Scourfield | J. Scourfield | J. Scourfield |
| Pembroke Boroughs | H. Owen | H. Owen | H. Owen | Graham | J. Owen | J. Owen | → | → | → | → | → | → | → | → | → |
| Pembrokeshire | J. Owen | J. Owen | J. Owen | J. Owen | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell | J. Campbell |
| Carmarthen | Yelverton | Lewis | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris | D. Morris |
| Carmarthenshire | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | Rice-Trevor | D. Jones | D. Jones | D. Jones | D. Jones | D. Jones | D. Jones |
| Carmarthenshire | Adams | Hamlyn-Williams | J. Jones | J. Jones | J. Jones | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. A. Davies | D. Pugh |

### 1859 to 1885

Conservative  Liberal
| Constituency | 1859 | 61 | 64 | 1865 | 66 | 1868 | 1874 | 76 | 78 | 1880 | 82 |
| Cardigan Boroughs | E. Pryse | E. Pryse | E. Pryse | E. Pryse | E. Pryse | T. Lloyd | D. Davies | D. Davies | D. Davies | D. Davies | D. Davies |
| Cardiganshire | W. T. Powell | W. T. Powell | W. T. Powell | T. Lloyd | T. Lloyd | Richards | T. E. Lloyd | T. E. Lloyd | T. E. Lloyd | L. Pugh | L. Pugh |
| Haverfordwest Bors | J. Scourfield | J. Scourfield | J. Scourfield | J. Scourfield | J. Scourfield | Edwardes | Edwardes | Edwardes | Edwardes | Edwardes | Edwardes |
| Pembroke Boroughs | J. Owen | H. Owen jr | H. Owen jr | H. Owen jr | H. Owen jr | Meyrick | Reed | Reed | Reed | Allen | Allen |
| Pembrokeshire | J. Campbell | G. Phillips | G. Phillips | G. Phillips | Bowen | J. Scourfield | J. Scourfield | Bowen | Bowen | W. Davies | W. Davies |
| Carmarthen | D. Morris | D. Morris | W. Morris | W. Morris | W. Morris | Cowell-Stepney | Nevill | Cowell-Stepney | Williams | Williams | Jenkins |
| Carmarthenshire | D. Jones | D. Jones | D. Jones | D. Jones | D. Jones | Sartoris | F. Campbell | F. Campbell | F. Campbell | F. Campbell | F. Campbell |
| Carmarthenshire | D. Pugh | D. Pugh | D. Pugh | D. Pugh | D. Pugh | John Jones of Llandovery | John Jones of Llandovery | John Jones of Llandovery | John Jones of Llandovery | Powell | Powell |

### 1885 to 1918

Conservative  Liberal  Liberal Unionist
| Constituency | 1885 | 1886 | 89 | 90 | 1892 | 1895 | 98 | 1900 | 1906 | 08 | Jan 1910 | Dec 1910 | 12 |
| Cardiganshire | D. Davies | Rowlands | Rowlands | Rowlands | Rowlands | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies | Vaughan-Davies |
| Carmarthen District | Jenkins | Cowell-Stepney | Cowell-Stepney | Cowell-Stepney | Jones | Jenkins | Jenkins | A. Davies | Williams | Williams | Williams | Williams | Williams |
| Carmarthenshire East | Pugh | Pugh | Pugh | Thomas | Thomas | Thomas | Thomas | Thomas | Thomas | Thomas | Thomas | Thomas | Towyn Jones |
| Carmarthenshire West | Powell | Powell | Morgan | Morgan | Morgan | Morgan | Morgan | Morgan | Morgan | Morgan | Morgan | Hinds | Hinds |
| Pembroke and Haverfordwest District | H. Allen | Mayne | Mayne | Mayne | C. Allen | Laurie | Laurie | Laurie | Philipps | Philipps | Philipps | Guest | Guest |
| Pembrokeshire | W. Davies | W. Davies | W. Davies | W. Davies | Rees-Davies | Rees-Davies | Philipps | Philipps | Philipps | Roch | Roch | Roch | Roch |

### 1918 to 1950

Coalition Liberal (1918-22) / National Liberal (1922-23)  Conservative  Independent Liberal  Independent Liberals (1931)  Labour  Liberal
| Constituency | 1918 | 21 | 1922 | 1923 | 24 | 1924 | 26 | 28 | 1929 | 1931 | 32 | 1935 | 36 | 41 | 1945 |
| Cardiganshire | Vaughan-Davies | E. Evans | E. Evans | Morris | Morris | → | → | → | → | → | O. Evans | O. Evans | O. Evans | O. Evans | Bowen |
| Carmarthen | Hinds | Hinds | Hinds | Ellis-Griffith | Mond | Mond | → | W. Jones | Hopkin | R. Evans | R. Evans | Hopkin | Hopkin | Hughes | Morris |
| Llanelli | Towyn Jones | Towyn Jones | Williams | Williams | Williams | Williams | Williams | Williams | Williams | Williams | Williams | Williams | Griffiths | Griffiths | Griffiths |
| Pembrokeshire | E. Jones | E. Jones | G. Lloyd-George | → | → | Price | Price | Price | G. Lloyd-George | → | → | → | → | → | → |

### 1950 to 1983

Conservative  Democratic  Independent  Labour  Liberal  Plaid Cymru
| Constituency | 1950 | 1951 | 1955 | 57 | 1959 | 1964 | 1966 | 66 | 68 | 69 | 1970 | Feb 1974 | Oct 1974 | 1979 |
| Cardiganshire | Bowen | Bowen | Bowen | Bowen | Bowen | Bowen | Morgan | Morgan | Morgan | Morgan | Morgan | Howells | Howells | Howells |
| Carmarthen | Morris | Morris | Morris | M. Lloyd George | M. Lloyd George | M. Lloyd George | M. Lloyd George | G. Evans | G. Evans | G. Evans | G. Jones | G. Jones | G. Evans | Thomas |
| Llanelli | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Griffiths | Davies | Davies | Davies | Davies |
| Pembrokeshire | Donnelly | Donnelly | Donnelly | Donnelly | Donnelly | Donnelly | Donnelly | Donnelly | → | → | Edwards | Edwards | Edwards | Edwards |

### 1983 to present

Conservative  Labour  Liberal  Liberal Democrats  Plaid Cymru
| Constituency | 1983 | 1987 | 88 | 1992 | 1997 | 00 | 2001 | 2005 | 2010 | 2015 | 2017 | 2019 | 20 | 2024 |
| Carmarthen / Carmarthen East and Dinefwr (1997) / Caerfyrddin (2024) | R. Thomas | A. Williams | A. Williams | A. Williams | A. Williams | A. Williams | Price | Price | J. Edwards | J. Edwards | J. Edwards | J. Edwards | → | Davies |
| Ceredigion and Pembroke North / Ceredigion (1997) / Ceredigion Preseli (2024) | Howells | Howells | → | Dafis | Dafis | S. Thomas | S. Thomas | M. Williams | M. Williams | M. Williams | Lake | Lake | Lake | Lake |
| Llanelli | Davies | Davies | Davies | Davies | Davies | Davies | Davies | Griffith | Griffith | Griffith | Griffith | Griffith | Griffith | Griffith |
| Pembrokeshire / Preseli Pembrokeshire (1997) / Mid and South Pembrokeshire (2024) | N. Edwards | Bennett | Bennett | Ainger | Lawrence | Lawrence | Lawrence | Crabb | Crabb | Crabb | Crabb | Crabb | Crabb | Tufnell |
| Carmarthen West and South Pembrokeshire | | | | | Ainger | Ainger | Ainger | Ainger | Hart | Hart | Hart | Hart | Hart | N/A |