Merthyr Tydfil & Aberdare is currently held by the Labour Party, and awaits results.
Results for 2019 are notional estimates based on the new boundaries.
| Votes | Share % | Change %pts. | ||
|---|---|---|---|---|
| Anthony Cole Workers Party of Britain | − | − | − | |
| David Griffin Green | − | − | − | |
| Gerald Jones Labour | − | − | − | |
| Jade Smith Liberal Democrat | − | − | − | |
| Francis Whitefoot Plaid Cymru | − | − | − | |
| Bob Davenport Communist Party of Britain | − | − | − | |
| Lorenzo De Gregori Independent | − | − | − | |
| Amanda Jenner Conservative | − | − | − | |
| Gareth Thomas Reform UK | − | − | − |