The Church of Ireland parish church that occupies a low rise in Newcastle Middle, with a steep drop on the northern side, dates from the late eighteenth or early nineteenth century. It looks, from the outside, like a modest rural church of its era. Yet the ground it stands on carries a much older story, and almost nothing visible remains to tell it.

The medieval foundation on or near this site was granted to the convent of Grace Dieu by John Comyn, Archbishop of Dublin, sometime between 1181 and 1212. Grace Dieu was an Augustinian nunnery north of Dublin, and the grant connected this Wicklow site to that community's network of properties. The church formed part of the medieval borough of Newcastle, a settlement of some significance in its day. None of the medieval fabric survives, and the current building may simply occupy the same ground by coincidence as much as by continuity. What does survive is the triangular graveyard, bounded by a modern wall and flanked by the public road on the western and northern sides. It holds a considerable number of early eighteenth-century headstones, and at the eastern end of the church, the base of a seventeenth-century headstone, partially legible, records a date of 1699 alongside fragments of letters that resist full reconstruction. That eroded fragment is, in a sense, the oldest thing you can see here, a remnant that outlasted the medieval church, the convent's influence, and whatever came between.