Cefn may refer to:
Places Cefn (community), in Wrexham county borough, Wales Cefn Mawr, a large village in the community of Cefn Cefn Cribwr, a village in Bridgend county borough, Wales Cefn Fault, a geological fault in Wales Cefn Glas, an area of Bridgend, Wales Cefnllys or Cefn Llys, an abandoned ghost village, formerly a medieval castle town and borough, near Llandrindod Wells, Powys Cefnllys Castle
Sport Cefn Druids A.F.C., a football club based in Cefn Mawr, playing in the Cymru Alliance. F.C. Cefn, a football club based in Cefn Mawr, playing in the Welsh National League (Wrexham Area) Premier Division
Other uses Cefn quarry, a slate quarry near Cilgerran, Wales