Votes cast in the South Wales Central region. These votes are used to apportion additional members to parties unrepresented in the constituency vote.
| Conservative | 56,662 | 22.1% | +5.6% | 2 | ||
| Plaid Cymru | 46,478 | 18.2% | -0.7% | 2 | ||
| Labour | 102,611 | 40.1% | +9.5% | 0 | ||
| Green | 14,478 | 5.7% | +2.6% | 0 | ||
| Liberal Democrat | 11,821 | 4.6% | -1.2% | 0 | ||
| Abolish the Welsh Assembly | 8,396 | 3.3% | -0.3% | 0 | ||
| Propel | 5,552 | 2.2% | +2.2% | 0 | ||
| UKIP | 3,127 | 1.2% | -8.2% | 0 | ||
| Reform UK | 2,244 | 0.9% | +0.9% | 0 | ||
| No More Lockdowns | 1,298 | 0.5% | +0.5% | 0 | ||
| Gwlad | 1,098 | 0.4% | +0.4% | 0 | ||
| Communist | 602 | 0.2% | +0.2% | 0 | ||
| Independent | 580 | 0.2% | -0.1% | 0 | ||
| TUSC | 519 | 0.2% | -0.1% | 0 | ||
| Workers Party | 411 | 0.2% | +0.2% | 0 |
View the 8 seats elected by first-past-the-post in South Wales Central in 2021.
| Cardiff Central | Lab hold | ||
| Cardiff North | Lab hold | ||
| Cardiff South and Penarth | Lab hold | ||
| Cardiff West | Lab hold | ||
| Cynon Valley | Lab hold | ||
| Pontypridd | Lab hold | ||
| Rhondda | Lab gain from PC | ||
| Vale of Glamorgan | Lab hold |