Regional Member changes to the Senedd
# Regional Member changes to the Senedd

This is a list of Regional Member changes (co-options) to the Senedd (Welsh Parliament; Welsh:Senedd Cymru; formerly the National Assembly of Wales before 2020). Under the provisions of the Government of Wales Act, 1998, regional members of the Senedd who resign, die or are otherwise disqualified are replaced by the next available and willing person of their original party's list, and no by-election occurs.

These are the co-options that have occurred since the first elections in 1999.

| Assembly / Senedd term | Region | Date (that new member took the oath) | Incumbent | Party | Replacement | Party | Cause |
| - | - | - | - | - | - | - | - |
| 1999–2003 | Mid and West Wales | 1 May 2000 | Alun Michael | Labour | Delyth Evans | Labour | Resignation to concentrate on his post as Member of Parliament |
| 1999–2003 | North Wales | 22 March 2001 | Christine Humphreys | Liberal Democrats | Eleanor Burnham | Liberal Democrats | Resignation on health grounds |
| 1999–2003 | North Wales | 10 Sept 2002 | Rod Richards | Conservative | David Jones | Conservative | Resignation on health grounds (Alcoholism) |
| 2007–2011 | South Wales East | 30 June 2010 | Mike German | Liberal Democrats | Veronica German | Liberal Democrats | Resignation on appointment to House of Lords |
| 2011–2016 | South Wales West | 19 May 2015 | Byron Davies | Conservative | Altaf Hussain | Conservative | Resignation on 15 May 2015 due to election as MP for Gower |
| 2011–2016 | North Wales | 27 May 2015 | Antoinette Sandbach | Conservative | Janet Haworth | Conservative | Resignation on 8 May 2015 due to election as MP for Eddisbury |
| 2016–2021 | North Wales | 28 Dec 2017 | Nathan Gill | UKIP | Mandy Jones | UKIP | Resignation on 27 December 2017 to concentrate on his post as Member of the European Parliament |
| 2016–2021 | Mid and West Wales | 2 August 2018 | Simon Thomas | Plaid Cymru | Helen Mary Jones | Plaid Cymru | Resignation on 25 July 2018 due to arrest for possession of indecent images |
| 2016–2021 | South Wales East | 8 February 2019 | Steffan Lewis | Plaid Cymru | Delyth Jewell | Plaid Cymru | Death from bowel cancer on 11 January 2019 |
| 2016–2021 | South Wales East | 6 July 2020 | Mohammad Asghar | Conservative | Laura Anne Jones | Conservative | Death on 16 June 2020 |

No co-options occurred during the Second Assembly (2003–2007).

