The present building contains a 12th-century baptismal font, indicating the presence of a church at that time, although extensive rebuilding in 1867 removed the datable features of the previous edifice.

St Cynfarwy's Church is set within a churchyard at the side of the road in the centre of Llechgynfarwy, a hamlet in Anglesey, north Wales.

[3][6] On 5 November 1349, the possessions of the deceased clergyman who had been the incumbent priest of Llechgynfarwy were dealt with by an inquisition at Beaumaris, Anglesey – one of several dead clergymen whose goods were considered that day.

According to the historian Antony Carr, the timing suggests that the priests had been victims of the Black Death, and he notes that "the clergy as a class were hit particularly hard" by it.

[3][4] Kennedy's work, which rebuilt the church "almost from the foundations" in the words of a 2009 guide to the buildings of the region, left no datable features.

[9] People associated with the church include Owen Humphrey Davies, a 19th-century composer, conductor and quarry worker, who became a clergyman in his late forties.

[8] The east window has two lights with three trefoils in the decorative stone tracery at the top, set in an arched frame with a hoodmould on the outer wall.

[3][8] A survey in 1937 by the Royal Commission on Ancient and Historical Monuments in Wales and Monmouthshire also noted a brass plate by the north nave window commemorating the 18th-century bequest of a Catherine Roberts to "two old housekeepers of unblemished character".

It has a large inscribed brass plate set in marble showing the genealogical links between the Bold family and the Tudor dynasty.