Glyn Ceiriog is the principal settlement of the Ceiriog Valley and a community in Wrexham County Borough, north-east Wales. Glyn Ceiriog translates simply as Ceiriog Valley, though there are other villages in the valley. The village and community is technically known, in traditional Welsh naming style, as Llansantffraid Glyn Ceiriog or sometimes Llansanffraid Glyn Ceiriog, which means church of St Ffraid in the Ceiriog Valley, but it has come to be known simply as Glyn Ceiriog, or even Glyn for short. The name Llansanffraid is now more associated with other villages of the same name.

Wrexham County Borough is a county borough, with city status, in the north-east of Wales. It borders the English ceremonial counties of Cheshire and Shropshire to the east and south-east respectively, Powys to the south-west, Denbighshire to the west and Flintshire to the north-west. The city of Wrexham is the administrative centre. The county borough is part of the preserved county of Clwyd.