This is a List of Welsh principal areas by population density in the 2001 UK census.

Rank	Area	People / km²
1	Cardiff	4263
2	Newport	734
3	Torfaen	717
4	Blaenau Gwent	631
5	Caerphilly	614
6	Swansea	597
7	Rhondda Cynon Taff	547
8	Bridgend	530
9	Merthyr Tydfil	496
10	Vale of Glamorgan	365
11	Flintshire	343
12	Neath Port Talbot	307
13	Wrexham	261
14	Denbighshire	113
15	Monmouthshire	103
16	Conwy	99
17	Anglesey	96
18	Carmarthenshire	74
19	Pembrokeshire	74
20	Gwynedd	46
21	Ceredigion	44
22	Powys	25

See also

• List of Welsh principal areas by population
• List of Welsh principal areas by area