"A hamlet, in that part of the parish of Gresford which is in the hundred of Bromfield, county of Denbigh; 5 miles (N by W) from Wrexham; containing 539 inhabitants. It is situated near the left bank of the river Alyn, and on the border of Flintshire. ..... Offa's Dyke passes between the township and the river."
[ A Topographical Dictionary of Wales, 1833 & 1849, Samuel Lewis]
Llay became a parish of the Church in Wales on 13 December 1944. It was formed from the township of Llay, and parts of the townships of Burton, Gresford, and Marford & Hoseley, which, until then, been in the parish of Gresford.