The River Lliedi (Welsh: Afon Lliedi) has its source in the hills near Llanelli and Llannon in Carmarthenshire, Wales. The river fills the Swiss Valley reservoir and meets the sea at the Bury estuary at the former Carmarthenshire Dock, Llanelli.
The river's tidal course near Llanelli has been altered several times over the last 200 years to build docks to serve the large tinplate and coal mining industries of the town.
Coordinates: 51°43′24″N 4°09′50″W / 51.72328°N 4.16399°W