Abercynon Ward by-election
| Candidate | Party | Votes | Result |
|---|
| BAXTER Jeffrey Lee |
Green Party / Plaid Werdd |
18 |
|
| DENNIS Andrew James |
Welsh Labour / Llafur Cymru |
520 |
Elected |
| ROBINSON Adam |
Welsh Conservative Party Candidate / Ymgeisydd Plaid Geidwadol Cymru |
56 |
|
| SKINNER Matt |
Plaid Cymru - The Party of Wales |
56 |
|