Knockraha is within the Roman Catholic parish of Glounthaune, which was formed in the late 19th century with the amalgamation of the historical ecclesiastical parishes of Ballylucra, Ballyvinney, Caherlag, Killaspugmillane and Kilquane. The latter parish of Kilquane stretched from Glenmore Bridge to Watergrasshill village and was centred on the church in what is now Kilquane Cemetery. Tradition holds that Saint Cuan founded Kilquane, which means 'church of Cuán', and there are several other Kilquanes elsewhere in Munster. Cuan was possibly a passing missionary, like Saint Patrick, who brought Christianity to the area.
