The surrounding structure dates from around 1780, with a chancel added in 1868, but the south door is considerably older, a re-used piece from the sixteenth or seventeenth century whose jambs carry a carved decoration of vertebrate tulip stems, meaning stylised plant forms with segmented, almost anatomical stalks. It is the sort of detail that passes unnoticed at a glance but rewards a closer look, a fragment of an earlier building quietly absorbed into a later one.

The site itself has an exceptionally long ecclesiastical history. Croom, recorded variously as Cromadh, Cromych, and Cromothe across the centuries, was the chief seat of the Uí Cairbre Aobhdha and was burned by Torlough O'Connor in 1151. A church here is documented from at least 1291, and the surrounding lands passed through several hands, including Maurice Fitzgerald, who held Crumech Castle and its lands in 1215, and Basilia Thursteyn, who held a portion of the lands in 1323. A succession of named rectors fills the later medieval record: John Route in 1376, Thomas Hunter in 1408, and a sequence of appointments in the 1550s that became briefly contentious when William O'Hurnley was recorded as having usurped the rectorship before Donald Kean was formally installed in 1552. By 1837, the antiquary Samuel Johnson noted that the church appeared to have been erected on the site of a larger building, and that the Ecclesiastical Commissioners had recently granted just over £151 for its repair. The Board of First Fruits, a body that funded the construction and repair of Church of Ireland buildings during the eighteenth and early nineteenth centuries, was responsible for the c. 1780 structure that still stands.

The church is now disused and sits on the western bank of the Maigue in Croom town. The three-stage square tower to the west and the three-bay nave are the most visible features from the outside. Anyone with an interest in carved stonework should look carefully at the south door, where the tulip stem decoration on the lower jambs survives as one of the more quietly unusual pieces of architectural carving in the county.