That designation alone sets it apart from the ordinary run of rural parish churches, suggesting something in its fabric, its history, or its setting warranted closer attention from those who catalogue such things.

Knockadrum sits in a part of Connacht where the landscape itself carries deep layers of settlement, from early medieval enclosures to post-Reformation Catholic practice conducted, for much of its history, under considerable legal and social pressure. Catholic church buildings that survive from the eighteenth or early nineteenth century in rural Galway often began as modest structures, plain-walled and without towers, built quickly and cheaply during a period when the Penal Laws, though easing, still cast a long shadow over Catholic institutional life. Whether this church belongs to that early wave of post-Penal construction or to the later Victorian period of more confident Catholic building is a question the available record does not yet answer in full.