The Clwydian Range (Welsh: Bryniau Clwyd; also known as the Clwydian Hills; or simply the Clwyds) is a series of hills in the north-east of Wales that runs from Llandegla in the south to Prestatyn in the north; the highest point is 554 m (1,818 ft) Moel Famau. The range forms the north-western part of the Clwydian Range and Dee Valley Area of Outstanding Natural Beauty.

The Clwydian Hills are formed from an upstanding block of deep sea sediments formed during the Silurian period as debris slurries originating on the nearby continental shelf. The older mudstones and siltstones of the Nantglyn Flags Formation form parts of the west-facing scarp slope and the overlying Elwy Formation, which consists of mudstones and siltstones deposited in deep marine conditions with numerous sandstone beds, forms most of the higher ground. Both formations are of Ludlovian age. The range's rocks are intensely faulted; the major Vale of Clwyd Fault is responsible for the impressive west-facing scarp of the Clwydian Range. It downthrows the rocks to the west and separates the younger Carboniferous and Permo-Triassic rocks of the Vale of Clwyd from those of the hills.

Ice from the Welsh ice-sheet moved eastwards over the Clwydian Hills during the last ice age, impinging on the Irish Sea Ice to the east of the range. Numerous glacial meltwater channels occur around the range whilst the valley of the River Wheeler which cuts the range in two was a significant drainage channel.

The hills in the Clwydian Range provide extensive views across northern Wales, to the high peaks of Snowdonia, eastwards across the Cheshire Plain to the Peak District, and towards Manchester and Liverpool in England to the northeast. The Offa's Dyke National Trail traverses the range's high ground from Llandegla to Prestatyn.

The hills, which are mainly heather-clad upland above pastures, have six Iron Age hillforts including Y Foel (Moel Hiraddug), Moel-y-gaer, Penycloddiau, Moel Arthur, a second Moel y Gaer and Foel Fenlli. There are several tumuli and cairns on the hills.

#	Peak	Elevation (m)	Grid reference
1	Bryn Coed yr Esgob	211	SJ068812
2	Moel Hiraddug	265	SJ063785
3	Mynydd y Cwm	300	SJ073768
4	Moel Maenefa	290	SJ085745
5	Moel y Gaer	206	SJ095708
6	Moel y Parc	398	SJ114703
7	Penycloddiau	440	SJ127678
8	Moel Plas-yw	420	SJ152669
9	Moel Arthur	456	SJ145661
10	Moel Llys-y-coed	465	SJ145655
11	Moel Dywyll	475	SJ151632
12	Moel Famau	554	SJ161626
13	Moel y Gaer	339	SJ148617
14	Moel Fenlli	511	SJ162600
15	Moel Eithinen	434	SJ168592
16	Gyrn	384	SJ165586
17	Moel Gyw	467	SJ171575
18	Moel Llanfair	447	SJ169566
19	Moel y Plâs	440	SJ170554
20	Moel y Gelli	361	SJ166545
21	Moel y Waun	412	SJ168534
22	Moel yr Acre	400	SJ169525

The Clwydian Range was designated as an Area of Outstanding Natural Beauty in 1985, one of only five in Wales. The original area was 167 square kilometres (64 sq mi), but in 2011 the area was extended southwards by a further 229 square kilometres (88 sq mi) to include the Dee Valley, Moel y Gamelin, the Horseshoe Pass and Castell Dinas Bran, the towns of Llangollen and Corwen, the Pontcysyllte Aqueduct, Chirk Castle and Valle Crucis Abbey. The AONB now extends to 389 square kilometres (150 sq mi).

A wide range of wildlife thrives in the range, including red kites and red foxes, which both prey on rabbits and voles. There is also one of the few Welsh populations of black grouse and there is a project to conserve the European water vole, which is suffering a large decline in numbers across the United Kingdom. Another project is trying to get rid of the non-native Himalayan balsam which has invaded the Alyn Valley area.

The Offa's Dyke Path follows the Clwydian Range, although Offa's Dyke itself was not constructed on it. The Clwydian Way long distance footpath passes through the Clwydian Range, and the North Wales Path follows the foot of the scarp between Prestatyn and Dyserth.

• Clwydian Range and Dee Valley AONB
• Clwydian Range Tourism Group

53°11′N 3°15′W / 53.183°N 3.250°W / 53.183; -3.250