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

Clwyd catchment

Conwy catchment

Simple coastal catchments

Aber catchment

Ogwen catchment

Cegin catchment

Adda catchment

Isle of Anglesey rivers

Anticlockwise from Menai Bridge / Porthaethwy

Minor coastal catchments

Crigyll catchment

Ffraw catchment

Cefni catchment

Braint (i) catchment

The Afon Braint bifurcates near Llanfairpwllgwyngyll to form two different watercourses.

Braint (ii) catchment

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

Seiont catchment

Gwyrfai catchment

Simple coastal catchments

Rivers flowing into Cardigan Bay

From the tip of the Llŷn Peninsula to St. David's Head

Daron catchment

Soch catchment

Rhyd-hir catchment etc

Dwyfor catchment

Glaslyn catchment

Artro catchment

Ysgethin catchment

Mawddach catchment

Dysynni catchment

Dyfi catchment

Clarach catchment

Rheidol catchment

Ystwyth catchment

Wyre catchment

Cledan catchment

Arth catchment

Aeron catchment

Coastal streams

Teifi catchment

Nyfer catchment etc

Minor coastal catchments

Rivers flowing to west Pembrokeshire coast

From St David's Head to St. Govan's Head

Minor catchments

Cleddau catchment

Rivers flowing into the Bristol Channel

From St. Govan's Head to M48 Bridge

South Pembrokeshire rivers

Taf catchment

Towy catchment

Gwendraeth catchment

Lliedi catchment

Loughor catchment

Clyne catchment

Tawe catchment

Neath catchment

Afan catchment

Kenfig catchment

Ogmore catchment

Col-huw catchment

Thaw catchment

Cadoxton catchment

Taff catchment

Rhymney catchment

Usk catchment

Wye catchment

Severn catchment

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.

Longest rivers in Wales

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.