Penychen was a possible minor kingdom of early medieval Wales and later a cantref of the Kingdom of Morgannwg. Penychen was one of three cantrefs that made up the kingdom of Glywysing, the other two being Gwynllwg and Gorfynydd. The cantrefi were created on the death of Glywys (c.480 AD), the first king of Glywysing, when the kingdom was divided between three of his sons, Pawl, Gwynllyw and Mechwyn.