Claremorris takes its name from the Norman, Maurice de Prendergast. He came to Ireland with Strongbow in 1170, and was granted large tracts of land around the Claremorris area. His son, Gerard is reputed to have built Brize Castle.

The correct title of the Parish is Kilcolman, so called in honour of St. Colman. This saint is reputed to have been born in the West of Ireland and to have received his religious training, first at Bangor and later at Iona. He eventually became Abbot of Iona. A controversy developed about the date of Easter and St. Colman held by the ancient Irish custom and he lost his case. He refused to abandon the practise of "the saintly elders of the Irish Church" and he left England, and retired to a small island in the West called Innisboffin. He built a monastery there. Difficulties developed there, and he left and founded a new monastery in Mayo Abbey. His Abbey there, was granted various portions of land, including lands at Kilcolman. Thus he became the patron Saint of Kilcolman Parish.

The Claremorris Church in 1911.

Little information is available regarding the progress of the building of the church. There is a suggestion of certain difficulties and disagreements arising which may have delayed the completion of the work. The report relating to the laying of the foundation stone states that it was hoped to complete the building in two years. The fact that it took seven years to complete, definitely lends credence to the suggestion of difficulties arising, but no evidence could be found of this. But certainly, something must have occurred that delayed the completion of the building from 1904 to 1911.