: ''For the river which flows into the River Loughor see

Afon Gwili (Loughor) The Afon Gwili is a right-bank tributary of the River Loughor in the east of Carmarthenshire, South Wales. It rises near Cross Hands before flowing in a generally southerly direction past the small village of Cwmgwili to join with the Loughor b ...

'' The River Gwili () in

Carmarthenshire Carmarthenshire (; or informally ') is a Principal areas of Wales, county in the South West Wales, south-west of Wales. The three largest towns are Llanelli, Carmarthen and Ammanford. Carmarthen is the county town and administrative centre. ...

, is a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

of the

River Towy The River Towy (, ; also known as the River Tywi) is one of the longest rivers flowing entirely within Wales. Its total length is . It is noted for its sea trout and salmon fishing. Route The Towy rises within of the source of the River Teif ...

, the longest river entirely in Wales. Its

headwater The headwater of a river or stream is the geographical point of its beginning, specifically where surface runoff water begins to accumulate into a flowing channel of water. A river or stream into which one or many tributary rivers or streams flo ...

is found east of

Llanllawddog Llanllawddog () is a community located in Carmarthenshire, south-west Wales. The population of the community taken at the 2011 census was 703, and at the 2021 census this had increased to 765.Community Council websit/ref> Llanllawddog is bord ...

, in the

Brechfa Forest The Brechfa Forest is a forest in Carmarthenshire, south Wales. Brechfa Forest is the 'modern' name for part of the ancient Glyn Cothi Forest. From before records began in the 6th century the communities in the 15 villages which encircle Glyn C ...

. It runs west, through

Llanpumsaint Llanpumsaint (; Welsh "Llan" church + "pum" five + "saint" saint(s)) is a village and community in Carmarthenshire, Wales. In the 2001 UK Census, Llanpumsaint community had a population of 595. It is not to be confused with Pumsaint, a small v ...

, to its confluence with the

River Duad A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

, just south of

Cynwyl Elfed Cynwyl Elfed (; sometimes Conwyl and formerly anglicised as Conwil Elvet or Conwil in Elvet) is a village and community in the county of Carmarthenshire, Wales. The community includes the villages of Cynwyl Elfed, Blaenycoed and Cwmduad. It i ...

village. Here its course turns to the southeast, running through

Bronwydd Bronwydd is a village and community in the county of Carmarthenshire, Wales, situated about three miles north of Carmarthen in the valley of the River Gwili. Bronwydd community comprises the village of Bronwydd Arms, a couple of nearby hamlets ...

before joining the River Towy at

Abergwili Abergwili () is a village and community (Wales), community in Carmarthenshire, Wales, near the confluence of the rivers River Towy, Towy and River Gwili, Gwili, close to the town of Carmarthen. It is also an Abergwili (electoral ward), electoral ...

. The River Gwili gives its name to a number of settlements, as well as the

Glangwili General Hospital Glangwili General Hospital (), previously known as West Wales General Hospital, is a general hospital in Carmarthen, Wales. It is managed by Hywel Dda University Health Board Hywel Dda University Health Board (HDUHB) () is the local health bo ...

. The Carmarthen Aberystwyth Line once followed the course of the river between Abergwili and Llanpumsaint and the dismantled railway line can still be seen right along the valley. In 1978 a section of the line was reopened in Bronwydd as a heritage railway and was given the name

Gwili Railway The Gwili Railway () is a Welsh heritage railway, that operates a preserved standard gauge heritage railway, railway line from the site of Abergwili Junction (near Carmarthen) in South West Wales, southwest Wales along a section of the former ...

References

Rivers of Carmarthenshire {{Wales-river-stub