The first white settlers of the district now known as Mayo were people from Ireland. They arrived between the years of 1820 and 1830 trekking their way overland from Montreal northward and westward on the Ottawa River to the Blanche and Lievre Rivers. It was natural for these settlers to name the rugged hilly terrain after the country from which they had emigrated – hence the name Mayo after County Mayo in Ireland. These settlers brought with them their Irish faith and were first ministered by Father John Brady from Buckingham. He served the people from 1834 – 1862 and built the first mission church of St. Malachy about 1855. St. Malachy was a 12th century Saint of Ireland and Primate of all Ireland as Archbishop of Armagh – the seat of St. Patrick’s bishopric.

St. Malachy was created a parish in 1888 with Father Dacier as first parish priest. The present church was built in 1896 by Father F. Brunet, later bishop of Mont Laurier. The first Irish settlers were buried in the burial plot on Church Street in Buckingham. Later parishioners were buried in the consecrated ground set apart in Mayo, which contains a beautiful life-size Crucifix, erected by Father Braceland and blessed by Father R. McCoy, W.F. who was a former parishioner.