This is a list of rivers of Wales, organised geographically, taken anti-clockwise, from the Dee Estuary through to the M48 Bridge that separates the estuary of the River Wye from the River Severn.
Tributaries are listed down the page in an upstream direction, starting with those closest to the sea. The main stem (or principal) river of a catchment is given, left-bank tributaries are indicated by (L), right-bank tributaries by (R). Note that, in general usage, the 'left (or right) bank of a river' refers to the left (or right) hand bank as seen when looking downstream. Where a named river is formed by the confluence of two differently named rivers, these are labelled as (Ls) and (Rs) for the left and right forks. A prime example is the formation of the River Taff from the Taf Fawr and the Taf Fechan at Cefn Coed-y-cymmer.
The list is essentially a list of the main rivers of Wales (as defined by the Environment Agency) and which more or less includes every watercourse named on Ordnance Survey mapping. Difficulties arise otherwise in determining what should and what should not be included.
Certain names are encountered frequently and particular care should be taken to differentiate between the various occurrences of Clydach, Clywedog and of Dulas for example as well as those whose names refer perhaps to the colour of their waters e.g. Afon Goch (red river), Afon Ddu (black/dark river ) and Afon Wen (white/light river).
Mainland rivers flowing into Liverpool Bay
From Dee Estuary to Garth Pier, Bangor, Gwynedd
River Dee, Wales (Afon Dyfrdwy)
Nant-y-fflint (L) (flows into Dee Estuary)
Wepre Brook (L) (flows into Dee Estuary)
Aldford Brook (R) (wholly in England)
River Alyn (L) (Afon Alun / River Alun)
River Cegidog (R) (Afon Cegidog)
Nant-y-Ffrith (R)
River Terrig (R) (Afon Terrig)
Worthenbury Brook (R)
Emral Brook (Ls)
Wych Brook (Rs) (formerly known as the "River Elfe")
Red Brook (L)
River Clywedog (L) (Afon Clywedog)
River Gwenfro (L) (Afon Gwenfro)
Glanyrafon Brook (R)
Black Brook (R) (Afon Ddu)
Shell Brook (R)
River Ceiriog (R) (Afon Ceiriog) (head of river is Ceiriog Ddu)
River Teirw (L) (Afon Teirw)
Nant Sarffle (R)
Nant Cwm-y-geifr (R)
Nant Cwm-llawenog (R)
Nant Rhydwilym (R)
River Eitha (L) (Afon Eitha)
Eglwyseg River (L)
Afon Morwynion (L)
River Alwen (L) (Afon Alwen)
Afon Ceirw (R)
Merddwr (R) (known as Nant Lleidiog upstream)
Afon Medrad (R)
Afon Brenig (L)
Afon Trystion (R)
Afon Llynor (R)
Afon Ceidiog (R)
Hirnant (R)
Afon Tryweryn (L) (River Tryweryn)
Afon Mynach (Dee) (L)
Afon Hesgyn (L)
Afon Gelyn (L) (flows into Llyn Celyn)
Nant Aberderfel (R) (flows into Llyn Celyn)
Afon Llafar (L) (flows into Bala Lake)
Afon Twrch (R)
Afon Lliw (L)
River Clwyd (Afon Clwyd)
Afon Gele (L)
River Elwy (L) (Afon Elwy)(Also known as Afon Cledwen above the village of Llangernyw)
Afon Meirchion (R)
River Aled (R)
Afon Gallen (Ls)
River Wheeler (R) (Afon Chwiler)
Afon Ystrad (R)
River Clywedog (Clwyd) (L) (Afon Clywedog) (Not to be confused with the Dee tributary of the same name)
River Conwy (Afon Conwy)
Afon Gyffin (L)
Afon Roe (L) (known as Afon Tafolog in upper reaches)
Afon Dulyn (L)
Afon Ddu (L)
Afon Garreg-wen (L)
Ffrwd Cerriguniawn (L)
Afon Melynllyn (R)
Afon Porth-llwyd (L)
Afon Eigiau
Afon Ddu (L)
Afon Crafnant (L)
Afon Geirionydd (R)
Afon Gallt y Gwg (R)
Nant y Goron (R)
Afon Llugwy (L)
Nantygwryd (R)
Afon Lledr (L)
Afon Wybrnant (R)
Afon Maesgwm (R)
Afon Ystumiau (L)
Afon Machno (L)
Afon Glasgwm (L)
Afon Iwrch (R)
Afon Eidda (L)
Merddwr (R)
Afon Caletwr (R)
Afon Serw (R)
Afon Gyrach
Afon Ddu
Afon Glan-sais (L)
Afon Maes-y-bryn (R)
Afon Aber
Afon Anafon (Rs)
Afon Rhaeadr Fawr (Ls)
Afon Rhaeadr Bach (Ls)
Afon Gam (L)
Afon Goch (Rs)
Afon Ogwen
Afon Caseg (R)
Afon Llafar (L)
Afon Denau (flows into Llyn Ogwen)
Nant Gwern y Gof (L)
Afon Lloer (flows into Llyn Ogwen)
River Cegin (Afon Cegin)
River Adda (Afon Adda)
Anticlockwise from Menai Bridge / Porthaethwy
Afon Cadnant (River Cadnant)
Nant Meigan
Lleiniog
Afon Nodwydd
Afon y Marchogion
Afon Lligwy
Nant Perfedd
Afon Goch (Dulas)
Nant y Beddyw
Afon Bryn Gwyn
Afon Goch (Amlwch)
Afon Wygyr
Gwter Fudr
Afon Alaw (River Alaw)
Afon Crigyll
Afon Caradog (L)
Afon Ffraw
Afon Frechwen (L)
Afon Gwna (flows into Llyn Coron)
Afon Cefni (River Cefni)
Afon Newydd (L)
Afon Ceint (L)
Afon Erddreiniog (L) (flows into Cefni Reservoir)
Afon Braint (River Braint, Dwyran)
Afon Rhyd y Valley (L)
Afon Braint (LlanfairPG)
Afon Rhyd Eilian (L)
Note "Afon Menai", known as the "Menai Strait" in English, is not technically a river, despite its Welsh name..
Mainland rivers flowing into the Menai Strait and Caernarfon Bay
From Bangor Pier to the tip of the Llŷn Peninsula
Afon Seiont (River Seiont) (known as Afon Rhythallt above Pont-Rhythallt)
Afon Nant Peris (flows into Llyn Peris)
Afon Arddu (L)
Afon Gwyrfai
Afon Carrog (L)
Afon Rhŷd (R)
Afon Llifon
Afon Llyfni, Lleyn
Afon Desach
Afon Hen
Nant Gwrtheyrn
Afon Geirch
Afon Amwlch
Afon Pen-y-graig
From the tip of the Llŷn Peninsula to St. David's Head
Afon Saint
Afon Daron
Afon Cyllyfelin (R)
Afon Soch
Afon Horon (L)
Afon Rhyd-hir
Afon Penrhos (R)
Afon Erch
Afon Wen
Afon Dwyfor
Afon Dwyfach (R)
Afon Henwy (L)
Afon Glaslyn
Afon Dwyryd (L) (Headwaters are disputed to be the Afon Goedol)
Afon y Glyn (L)
Afon Prysor (L)
Afon Cynfal (L)
Afon Teigl (Ls)
Afon Bowydd
Afon Tafarn Helyg
Afon Dylif
Afon Croesor (L)
Nanmor (L)
Afon Colwyn (R)
Afon Llynedno (L)
Afon Artro
Afon Cwmnantcol (L)
Afon Ysgethin
Afon Mawddach
Afon Dwynant (R)
Afon Gwynant (L)
Afon Cwm-llechen (R)
Afon Cwm-mynach (R)
Afon Wnion (L)
Afon Clywedog (L)
Afon Celynog (L)
Afon Wen (L)
Afon Gamlan (R)
Afon Eden (R)
Afon Crawcwellt (R)
Afon Gain (R)
Afon Dysynni (R)
Afon Fathew (L)
Afon Cadair (R)
Nant Gwernol (L)
Afon Dyfi (River Dovey)
Afon Leri (L)
Afon Ceulan (R)
Afon Einion (L)
Afon Llyfnant (L)
Afon Dulas (R) (North Dulas)
Afon Deri (R)
Afon Dulas (L) (South Dulas)
Afon Twymyn (L)
Afon Rhiwsaeson (R)
Afon Laen (L)
Afon Angell (R)
Afon Cleifion (L)
Afon Dugoed (Rs)
Afon Tafolog (Ls)
Afon Cerist (R)
Afon Cywarch (R)
Afon Clarach (formed at the confluence of Afon Stewi and Nant Silo)
Bowstreet Brook (R)
Afon Peithyll (Ls)
River Rheidol (Afon Rheidol)
Afon Melindwr (R)
River Mynach (L) (Afon Mynach)
Afon Merin (Rs)
Nant Rhuddnant (Ls)
Afon Castell (L)
Afon Llechwedd Mawr (flows into Nant y Moch Reservoir)
Afon Lluestgota (R)
Afon Hengwm (flows into Nant y Moch Reservoir)
Afon Hyddgen (R)
Nant-y-moch (stream flowing into Nant-y-moch Reservoir)
River Ystwyth (Afon Ystwyth)
Afon Fâd (L)
Afon Llanfihangel (R)
Nant Cynon (Ls)
Afon Magwr (R)
Nant Freuo (L)
Nant Pant-yr-Haidd (R)
Nant Cwmtarw (L)
Nant Cwm-nel (L)
Nant Cilmeddu (L)
Nant y Henfelin (L)
Nant yr Brithyll (R)
Nant y Berws (L)
Nant Cell (R)
Nant Lledwenau (R)
Nant Bwlchgwallter (L)
Nant Peiran (R)
Nant Crafanglach (R)
Nant Perfedd (L)
Nant Ffrin-fawr (Rs)
Nant Hylles (L)
Nant Gau (L)
Nant Ffrwd-ddu (L)
Nant Cae-glas (R)
Nant y Gwndwn-gwyn (Ls)
Nant Cwta (Rs)
Nant Milwyn (L)
Nant Byr (L)
Nant y Gwaith (R)
Nant Watcyn (R)
Nant yr Onnen (R)
Nant Cwm-du (L)
Nant Stwc (R)
Nant Penygwndwn (L)
Nant Garw (R)
Nant y Cae Isaf (L)
Nant y Cae (L)
Nant Troedyrhiw (R)
Afon Diliw (R)
Nant yr Gafod (R)
Diliw Fechan (R)
Nant y Caseg (L)
Nant yr Eglwys
Nant yr Eglwys-fach (L)
Nant Lwyd (R)
Nant y Gorlan (Rs)
Nant Llychese (R)
Nant Rhydyfelin (L)
Nant Ffos-casaf (L)
Afon Wyre
Afon Carrog (R)
Wyre Fach (L)
Nant Rhydrosser (L)
Afon Tryal (L)
Afon Beidog (L)
Afon Cledan
River Arth
Afon Aeron
Afon Mydr (L)
Gwenffrwd (R)
Afon Drywi
Afon Soden
Afon Fynnon Ddewi
Hoffnant
River Teifi (Afon Teifi)
Afon Piliau (L)
Nant Arberth (R)
Afon Cych (L)
Afon Dulas (L)
Afon Pedran (L)
Afon Sylgen (R)
Afon Hirwaun (R)
Nant Elfed (R)
Afon Ceri (R)
Afon Dulas (R)
Afon Bedw (L)
Nant Bargod (L)
Afon Tyweli (L)
Afon Talog (R)
Afon Clettwr (P)
Clettwr Fawr (Rs)
Clettwr Fach (Ls)
Nant Cledlyn (R)
Afon Duar (L)
Afon Granell (R)
Afon Dulas (R)
Afon Denys (R)
Nant Clywedog (L)
Clywedog-isaf (Ls)
Clywedog-ganol (Rs)
Clywedog-uchaf (R)
Afon Brefi (L)
Nant Bryn-maen (R)
Afon Berwyn (L)
Afon Groes (R)
Afon Fflur (L)
Camddwr (R)
Afon Meurig (R)
Nant Lluest (R)
Glasffrwd (L)
Nant Egnant (L)
Nant Rhydol (R)
Afon Nyfer
Nant Duad (R)
Afon Brynberian (L)
Afon Bannon (L)
River Gwaun (Afon Gwaun)
River Aer (L)
From St David's Head to St. Govan's Head
River Alun
River Solva (Afon Solfach)
Brandy Brook
Daugleddau (estuary is Daugleddyf or Milford Haven downstream)
Pembroke River (L)
Carew River (L)
Cresswell River (L)
Western Cleddau (Rs)
Millin Brook (L)
Merlin's Brook (R)
Cartlett Brook (L)
Knock Brook (R)
Camrose Brook (R)
Rudbaxton Water (L)
Spittal Brook (L)
Nant-y-coy Brook (R)
Afon Anghof (L)
Afon Glan-rhyd (R)
Nant y Bugail (L)
Afon Cleddau (upper reaches of Western Cleddau)
Eastern Cleddau (Ls)
Afon Syfynwy (R)
Afon Wern (R)
From St. Govan's Head to M48 Bridge
River Tâf (Afon Taf)
River Cywyn (Afon Cywyn) (L)
Afon Cynin (L)
Afon Dewi Fawr (L)
Afon Sien (R)
Afon Fenni (R)
Afon Gronw (L)
Afon Marlais (R)
River Towy (Afon Tywi)
Afon Gwili (R)
Afon Annell (R)
River Cothi (R) (Afon Cothi)
Afon Gorlech (R)
Afon Twrch (R)
Afon Marlais (R)
Afon Dulas (R)
Afon Cennen (L)
Afon Sawdde (L)
Afon Bran (L)
Afon Ydw (R)
Afon Dulais (R)
Afon Brân (L)
Cynnant Fawr (Rs)
Cynnant Fach (L)
Afon Lwynor (Ls)
Afon Crychan (L)
Afon Gwydderig (L)
Afon Gwenlais (R)
Gwenffrwd (R)
Nant Melyn (R)
Afon Doethie (R)
Afon Pysgotwr Fawr (R)
Afon Pysgotwr Fach (R)
Camddwr (R)
River Gwendraeth
Gwendraeth Fach (Rs)
Gwendraeth Fawr (Ls)
River Lliedi (Afon Lliedi)
River Loughor (Afon Llwchwr)
Burry Pill (L)
Afon Lliw (L)
Afon Llan (L)
Afon Gwili (R)
River Amman (L)
Afon Lash (R)
Afon Morlais (R)
Afon Dulais
Afon Camffrwd
Clyne River
River Tawe
Nant y fendrod (L)
Lower Clydach River (R)
Upper Clydach River (R)
River Egel (L)
Afon Twrch (R)
Nant Gwys (L)
Gwys Fawr (Ls)
Gwys Fach (Rs)
Nant Llynfell (R)
Nant y Llyn (R)
River Giedd (R)
Nant Cyw (L)
Nant Ceiliog (L)
Nant Llech (L)
Nant Llech Pellaf (L)
River Haffes (R)
Nant Byfre (L)
Nant y Llyn (R)
River Neath
River Clydach (R)
River Dulais (R)
Melin Cwrt Brook (L)
Clydach Brook (L)
Nedd Fechan (Rs)
Afon Pyrddin (R)
Afon Mellte (Ls)
Sychryd(L)
Afon Hepste (L)
Afon Llia (Rs)
Afon Dringarth (Ls)
River Afan
Ffrwd Wyllt (L)
Nant Cwm Wenderi
Afon Pelenna (R)
Nant Cregan
Afon Corrwg (R)
Afon Corrwg Fechan (R)
River Kenfig (Afon Cynffig)
River Ogmore (Afon Ogwr)
River Ewenny (L)
Afon Alun (L)
Afon Ewenny Fach (L)
Nant Canna (L)
Nant Crymlyn (R)
River Llynfi (R)
Nant y Gadlys (R)
Nant Cwm-du (L)
Afon Garw (R)
Afon Ogwr Fawr (Rs)
Afon Ogwr Fach (Ls)
Nant Iechyd (R)
Afon Col-huw
Ogney Brook (Rs)
Hoddnant (Ls)
Boverton Brook (Ls)
Llanmaes Brook (Rs)
River Thaw
Kenson River (L)
River Waycock (Ls)
Nant Llancarfan (Rs)
Nant y Stepsau (R)
Cadoxton River
Bullcroft Brook (Ls)
Wrinstone Brook (Rs - Only at confluence of Wrinstone Brook and Bullcroft Brook does the river become the Cadoxton)
East Brook (L)
Cold Brook, Cadoxton (R)
Nant yr Argae (Ls)
Sully Brook (L)
River Taff (Afon Tâf)
River Ely (Afon Elai) (R)
Afon Clun (L) (Nant Myddlyn in upper reaches)
River Rhondda (R) (Afon Rhondda)
Rhondda Fawr (Ls)
Rhondda Fach (Rs)
River Ritec (Afon Ritec)
Nant Clydach (R)
River Cynon (R) (Afon Cynon)
Afon Aman
Afon Dar
Afon Pennar
Bargoed Taf (L)
Nant Morlais
Taf Fechan (Ls)
Nant Ffrwd (Rs)
Rhymney River (Afon Rhymni)
Nant Bargod Rhymni (R)
River Usk (Afon Wysg)
Ebbw River (R) (Afon Ebwy)
Sirhowy River (R)
River Ebbw Fach (L)
Afon Llwyd (R)
Sôr Brook (R)
Olway Brook (L)
Berthin Brook (R)
Afon Gafenni (L) (River Gavenny)
River Clydach (R)
Grwyne Fawr (L)
Grwyne Fechan (R)
Rhiangoll (L)
Afon Claisfer (R)
Afon Crawnon (R)
Caerfanell (R)
Afon Menasgin (R)
Afon Cynrig (R)
Afon Honddu (L)
Afon Tarell (R)
Nant Cwm Llwch
Afon Ysgir (L)
Nant Brân (L)
Afon Cilieni (L)
Afon Senni (R)
Afon Crai (R)
Afon Hydfer (R)
River Wye (Afon Gwy)
River Trothy (R)
River Monnow (Afon Mynwy) (R)
River Dore (L)
Dulas Brook (R)
Worm Brook (L)
Afon Honddu (R)
Olchon Brook (R)
Escley Brook (L)
River Lugg (L) (Afon Llugwy)
River Frome (L)
River Kenwater
River Arrow (R)
Cynon Brook
Gilwern Brook
Gladestry Brook
Dulas Brook (R)
Afon Llynfi (R)
River Ennig (R)
Dulas (L)
Triffrwd (L)
Bachawy (L)
Afon Edw (L)
Duhonw (R)
Afon Irfon (R)
Afon Chwerfri (L)
Dulas (L)
Afon Cammarch (L)
Afon Dulas (R)
Afon Gwesyn (L)
Dulas Brook (L)
River Ithon (L) (Afon Ieithon)
Dulas (R)
Clywedog Brook (R)
Afon Aran (L)
Camddwr (L)
Afon Elan (R)
Afon Claerwen (R)
Rhiwnant (R)
Afon Arban (R)
Afon Claerddu (R)
Afon Gwngu (R)
Afon Marteg (L)
Afon Bidno (L)
Afon Tarennig (R)
With the exception of a small part of the Rea Brook, all tributaries of the Severn downstream of the confluence of the Severn and the Vyrnwy are wholly in England. For details see List of rivers of England.
River Severn (Afon Hafren), Bristol Channel (Mor Hafren)
Rea Brook (R) (small parts of upper catchment in Wales)
River Vyrnwy (L) (Afon Efyrnwy) (lowermost section in England)
Afon Tanat (L) (lowermost section in England)
Cynllaith (L) (part forms the border between Wales and England)
Afon Ogau
Afon Iwrch (L)
Afon Rhaeadr (L)
Afon Eirth (L)
Afon Cain (L)
Nant Fyllon (Ls)
Nant Alan (Rs)
Afon Banwy (R) (a.k.a. Afon Einion)
Afon Einion (R)
Afon Gam (R)
Afon Twrch (L)
Maerdy Brook (L)
New Cut/Guilsfield Brook (L)
Luggy Brook (L)
Camlad (R) (partly in England)
River Rhiw (Afon Rhiw) (L)
Afon Rhiw (north fork) (Rs)
Afon Rhiw (south fork)(Ls)
Llifior Brook (L)
The Mule (R) (Afon Miwl)
Bechan Brook (L)
Mochdre Brook (R)
Nant Rhyd-ros lan??
Afon Carno (L)
Afon Cerniog (R)
Afon Cledan (R)
Afon Trannon (L)
Afon Cerist (R)
Colwyn Brook (L)
Nant Feinion (R)
Wigdwr Brook (L)
Afon Clywedog (L)
Afon Biga (R) (flows into Clywedog Reservoir)
Afon Llwyd (R) (flows into Clywedog Reservoir)
Afon Dulas (R)
Afon Brochan (L)
Nant Cydros (R)
Rhydyclwydau Brook (R)
This is a table of the longest rivers wholly or partially in Wales. Rivers only partly in Wales are included in this table in italics. Note that river lengths given by different authorities vary due to the different ways in which the measurement is made or indeed estimated. That rivers are partly fractal in nature accounts for some variation and lengths can also vary slightly over time as meanders expand or are cut off where rivers run through broad flood-plains.
