Dyffryn Cennen is a community located in Carmarthenshire, Wales. The population of the community taken at the 2011 census was 1,176.
The community is bordered by the communities of: Manordeilo and Salem; Llangadog; Cwmamman; Llandybie; Llanfihangel Aberbythych; and Llandeilo, all being in Carmarthenshire.
It includes the villages of Ffairfach and Trapp.
The community is part of the Llandeilo electoral ward for elections to Carmarthenshire County Council.