River Gwili

For the river which flows into the River Loughor see Afon Gwili (Loughor)

The River Gwili (Welsh: Afon Gwili) is a river in Carmarthenshire, Wales. A tributary of Wales' largest river, the River Towy, it's headwater is found east of Llanllawddog, in the Brechfa Forest. It runs west, through Llanpumsaint, to its confluence with the River Duad, just south of Cynwyl Elfed village. Here its course turns to the southeast, running through Bronwydd before joining the River Towy at Abergwili.

The river gives its name to a number of settlements as well as the West Wales General Hospital, commonly known as Glangwili Hospital. 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 for tourists and was given the name Gwili Railway.

The River Gwili is popular with both anglers and canoeists.