Cefnethin Rugby Football Club (Welsh: Clwb Rygbi Cefneithin) is a Welsh rugby union team from Cefneithin, Ammanford, Carmarthenshire. Officially founded in 1929. Cefnethin RFC is a member of the Welsh Rugby Union and is a feeder club for the Llanelli Scarlets. The club fields a first, seconds and youth team.