Founded as a Franciscan Third Order Regular house, in which building was already under way by 1454, it was apparently home to a mixed community of brothers and sisters, an arrangement that was uncommon for the period. A late 16th-century inquisition recorded it in modest terms, as a thatched church with a cemetery, a dormitory, and two other thatched houses, which gives some sense of how unassuming the place must have looked even in its working days. The ruin that survives today tells a more architecturally layered story, set in undulating pasture in the northwest corner of a graveyard that continued to receive burials well into the 20th century.

The church itself, built of roughly coursed limestone, consists of a nave and chancel constructed in a single phase, consistent with the mid-15th-century founding date. The central tower and the southern transept are later insertions, added no later than the 16th century. The tower is the most technically interesting element; it occupies the full width of the church between nave and chancel, rising from four rectangular piers and narrowing as it climbs to roughly half the church's width. Its vault is a segmental wicker-centred construction, meaning the curved formwork over which the stonework was laid was made of woven wicker, a technique that left its impression in the finished surface. Higher up, the tower retains ogee-headed windows, the curved S-shaped arch form typical of late medieval Irish ecclesiastical work, along with water-spouts that once drained a wall-walk, though the battlements themselves are gone. A spiral staircase once connected the tower to the transept, but it is now entirely blocked. The transept, reached through a wide arch from the nave, preserves two side-altar recesses in its east wall, each fitted with a piscina, a small stone basin with a drainage hole used for disposing of water from the liturgy. Beneath the ivy that now covers much of the interior, faint traces of original painted plaster were noted as long ago as 1791 by the antiquarian Francis Grose. The O'Hara family, whose burial vault occupies the northwest corner of the chancel, left a more solid mark on the building; their 18th-century presence is one reminder that these ruins have served local communities in various ways across several centuries. A small dependent house at Kilcummin, roughly 5 kilometres to the west, fell within Court Abbey's sphere, and an earthwork rath lies only about 20 metres to the east-southeast, suggesting the site sits within a landscape with a much longer history of human use.