The Ceiriog Valley or Dyffryn Ceiriog is the valley of the River Ceiriog in north-east Wales. It is also the name of a ward of the County Borough of Wrexham Until 1974 the valley was part of the traditional county of Denbighshire; then it became part of the short-lived county of Clwyd, which was abolished in 1996. Geographically, parts of the Ceiriog Valley extend into Shropshire, England. The Ceiriog Valley runs west to east, south of the Vale of Llangollen. The valley receives relatively few tourists despite being only a few miles from the A5 road and being described by British Prime Minister David Lloyd George as "a little bit of heaven on earth".
The Ceiriog Valley is divided into three communities: Ceiriog Ucha; Glyntraian and Llansantffraid Glyn Ceiriog. The largest village in the Ceiriog Valley is Glyn Ceiriog (also known as Llansantffraid Glyn Ceiriog). Villages within the Ceriog Valley include:
Llansantffraid Glyn Ceiriog
- Glyn Ceiriog
Three notable Welsh poets have connections with the Ceiriog Valley: John Hughes (1832 – 1887) was born on a farm near Llanarmon Dyffryn Ceiriog; Huw Morus (1622 – 1709) was born and lived near Pandy in the Ceiriog Valley; and Rev. Robert Elis (1812 – 1875) was a Baptist minister in Glyn Ceiriog from 1838 until 1840. (Hughes took the middle name Ceiriog and also used it as his bardic name; Morus's bardic name was Eos Ceiriog – the Nightingale of Ceiriog; and Elis was better known by his bardic name, Cynddelw.) The Ceiriog Memorial Institute in the village of Glyn Ceiriog was built as a memorial to them all, and contains stained glass windows dedicated to each of their memories.
- Dewi Parry Jones & Robert Owen Jones, "100 Years in the Valley - Y Glyn a Fu" (1998)
- Dewi Parry Jones & Robert Owen Jones, "100 Years in the Valley Volume II - Y Glyn a Fu" (1999)
- Gordon Emery - Guide to the Maelor Way (1991) ISBN 1-872265-98-7