The following is a list of built-up areas in Wales by population according to the 2021 and 2011 Census.
This is a list of built-up areas as of the 2021 census. [1]
| Built-up area | Welsh name | Population |
|---|---|---|
| Cardiff | Caerdydd | 348,535 |
| Swansea | Abertawe | 170,085 |
| Newport | Casnewydd | 130,890 |
| Barry | Y Barri | 56,605 |
| Bridgend | Pen-y-bont | 51,760 |
| Cwmbran | Cwmbrân | 47,090 |
| Wrexham | Wrecsam | 44,785 |
| Llanelli | Llanelli | 42,155 |
| Neath | Castell-nedd | 40,730 |
| Merthyr Tydfil | Merthyr Tudful | 39,535 |
| Aberdare | Aberdâr | 37,675 |
| Caerphilly | Caerffili | 33,105 |
| Pontypridd | Pontypridd | 31,900 |
| Port Talbot | Port Talbot | 31,555 |
| Colwyn Bay | Bae Colwyn | 29,275 |
| Pontypool | Pont-y-pŵl | 29,070 |
| Penarth | Penarth | 28,395 |
| Rhyl | Y Rhyl | 26,990 |
| Ebbw Vale | Glynebwy | 19,630 |
| Maesteg | Maesteg | 18,335 |
| Tonypandy | Tonypandy | 17,210 |
| Bangor | Bangor | 16,990 |
| Connah's Quay | Cei Connah | 16,770 |
| Prestatyn | Prestatyn | 16,675 |
| Carmarthen | Caerfyrddin | 16,455 |
| Porthcawl | Porthcawl | 15,795 |
| Conwy | Conwy | 15,715 |
| Risca | Rhisga | 15,195 |
| Llandudno | Llandudno | 14,710 |
| Aberystwyth | Aberystwyth | 14,640 |
| Tredegar | Tredegar | 14,530 |
| Hawarden | Penarlâg | 14,280 |
| Milford Haven | Aberdaugleddau | 14,250 |
| Church Village | Pentre'r Eglwys | 14,155 |
| Gorseinon | Gorseinon | 14,110 |
| Pyle | Y Pîl | 14,075 |
| Abergavenny | Y Fenni | 13,695 |
| Buckley | Bwcle | 13,560 |
| Porth | Y Porth | 13,350 |
| Rhondda | Cwm Rhondda | 13,265 |
| Mountain Ash | Aberpennar | 13,000 |
| Rhosllanerchrugog | Rhosllanerchrugog | 12,785 |
| Flint | Y Fflint | 12,780 |
| Blackwood | Coed Duon | 12,620 |
| Haverfordwest | Hwlffordd | 12,085 |
| Chepstow | Cas-gwent | 11,935 |
| Sarn | Sarn | 11,870 |
| Ystrad Mynach | Ystrad Mynach | 11,855 |
| Holyhead | Caergybi | 11,755 |
| Tonyrefail | Tonyrefail | 11,440 |
| Newtown (Powys) | Y Drenewydd | 10,885 |
| Baglan | Baglan | 10,510 |
| Monmouth | Trefynwy | 10,325 |
| Abertillery | Abertyleri | 10,245 |