At most medieval Irish churches, a tower occupies the west end; here, one sits between the nave and the chancel, functioning not merely as a structural element but as what appears to have been a residential space. Three floors, each accessible by a mural stair rising through the wall thickness, were equipped with ogee-headed windows, corbelled wooden floors, wall cupboards, and what may be a fireplace at third-floor level. A sheela-na-gig, the carved grotesque female figure found on a number of medieval Irish church buildings, once decorated the south-west corner before being removed. The north wall of the church is laid directly onto bedrock, and immediately beyond it the rock was quarried away to make room for a road, a reminder of how intimately this building was woven into the working landscape around it.

The church sits on the crest of a north-south ridge at the southern end, roughly at the centre of what was once a medieval village, with Kiltinan Castle visible around 270 metres to the east. Its documented history begins around 1195, when Robert, Bishop of Waterford, granted it to the Augustinian canons of St. Mary's Abbey at Osney in Oxfordshire. The Augustinians were a religious order of canons living under a rule derived from St. Augustine, and Osney was a significant English house of the order. The grant was reaffirmed in 1220 and again around 1230, and the church appears in the Papal Taxation Records of approximately 1302 and 1306, as well as in a 1316 register connected with the Hospital of St. John the Baptist in Dublin, another Augustinian foundation. The limestone doorways and windows, with their punch-tooling within drafted margins, point to a sixteenth-century phase of modification, and it is likely that what now reads as the nave was actually constructed at that time, possibly as a Reformation-era church built against the pre-existing tower. Older stonework, including a sandstone window that may date to the fourteenth century and masonry with diagonal tooling, has been reused in the later fabric. Two medieval graveslabs survive within the chancel area, and a seventeenth-century graveslab lies in the rectangular graveyard that extends southward from the church.