What it actually occupies is considerably older ground: the site of a medieval church known as Kilflin, a place of worship whose name echoes across more than six centuries of documentary record, each entry a slightly different spelling of a name that was already ancient when the scribes first wrote it down.

The antiquarian Thomas Johnson Westropp, writing in 1904 and 1905, compiled a sequence of historical references to the site that traces its identity through the layers of ecclesiastical Latin, anglicised Irish, and administrative record. The name appears as Keilfluing in 1410, then as Ecc Kyllin cum particula Sith Cathyll in 1418, and later as Catan, alias killin, in 1615, at which point it was recorded as mensal to the bishop, meaning it was held directly by the bishop to fund his household rather than assigned to a parish priest. The scholar John O'Donovan, working in the nineteenth century, rendered the Irish form as Cill Floinn, meaning Flin's church, suggesting the site took its original name from an early Christian figure called Flin or Flynn, possibly a local saint or founder. Westropp was clear that the Church of Ireland building of his own era sat directly on that ancient site.

Ballyorgan is a small settlement in the Ballyhoura uplands of south County Limerick, and the church is straightforward to locate in the village. Because the modern building was constructed on the medieval footprint, there is unlikely to be visible early fabric, but the layering of the site itself is worth pausing over. The sequence of place-name variants recorded by Westropp, moving from medieval Latin church documents through to seventeenth-century episcopal administration and finally to O'Donovan's Irish etymology, offers a quiet lesson in how a single patch of ground can carry the residue of very different recording traditions across the centuries.