This is a list of rivers of Wales, organised geographically. It is taken anti-clockwise from the Dee Estuary 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), and 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 includes more or less every watercourse named on Ordnance Survey mapping and thus many of the main rivers of Wales (as defined by Natural Resources Wales ). 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
Dee catchment
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)
Clwyd catchment
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)
Conwy catchment
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)
Simple coastal catchments
Afon Gyrach
Afon Ddu
Afon Glan-sais (L) Afon Maes-y-bryn (R)
Aber catchment
Afon Aber
Afon Anafon (Rs) Afon Rhaeadr Fawr (Ls) Afon Rhaeadr Bach (Ls) Afon Gam (L) Afon Goch (Rs)
Ogwen catchment
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)
Cegin catchment
River Cegin (Afon Cegin)
Adda catchment
River Adda (Afon Adda)
Isle of Anglesey rivers
Anticlockwise from Menai Bridge / Porthaethwy
Minor coastal catchments
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)
Crigyll catchment
Afon Crigyll
Afon Caradog (L)
Ffraw catchment
Afon Ffraw
Afon Frechwen (L) Afon Gwna (flows into Llyn Coron)