Cynog Glyndwr Dafis is a Welsh politician and member of Plaid Cymru who served as the Member of Parliament for Ceredigion from 1992 to 2000, originally as a joint Plaid Cymru–Green Party MP until 1997 and then only as a Plaid Cymru MP until 2000. He also served as the Member of the Welsh Assembly for Mid and West Wales from 1999 to 2003. Born Cynog Glyndwr Davies at Treboeth in Swansea, Glamorganshire, Wales, he was initially a school teacher and researcher before entering politics.

Plaid Cymru is a centre-left to left-wing, Welsh nationalist political party in Wales, committed to Welsh independence from the United Kingdom.