It is tub-shaped, carved from slaty limestone, and measures roughly 42 centimetres high by 56 centimetres wide, which gives it an almost squat, solid presence. The decoration is careful and considered: the upper edge of the front face carries cushion capitals, a rounded architectural detail borrowed from Romanesque stonework, and these give the top of the font an unexpectedly square appearance. Below them, the front face is worked into triangular panels that alternate between low and high relief, framed by raised mouldings. The sides and back carry sloping diamond patterns in low relief, and a raised band runs around the lower edge above a central drainage hole. The rim and the left front of the bowl are damaged, which is perhaps the only outward sign of the centuries this object has travelled.

The font is classified as early Norman or Romanesque in style, placing its likely origin somewhere in the twelfth or early thirteenth century, the period when the Normans were establishing themselves in Leinster and reshaping its ecclesiastical landscape. Where exactly it was made, and for which church, is not settled. One suggestion is that it was brought from a medieval church at nearby Glebe. A more probable explanation, put forward by archaeologist Chris Corlett, is that it came from a medieval church lying directly beneath the footprint of the present Church of Ireland building, a common situation in Irish towns where successive layers of Christian worship occupy the same ground. If that is correct, the font never really left its original parish at all; it simply outlasted the building that was raised around it and was set down in the grounds of its successor.