Croagh Patrick derives its name from the Irish Cruach Phádraig "(St) Patrick's stack", and is known locally as the Reek, which is a Hiberno-English word for a "rick" or "stack". In pagan times it was known as Cruachán Aigle, being mentioned by that name in the story of Cath Maige Tuired and in the Annals of Ulster entry for the year 1113. Cruachán is simply a diminutive of cruach "stack", but it is not certain what Aigle means. It is either from the Latin loan aquila "eagle" (more usually aicile or acaile) or a person's name. In addition to its literal meaning, cruach in the pagan name may also have some connection with Crom Cruach.
A seam of gold was discovered in the mountain in the 1980s: overall grades of of gold per tonne in at least 12 quartz veins, which could produce of ore. Mayo County Council elected not to allow mining, deciding that the gold was "fine where it was".
A Civil Defence survey conducted on 30 July 2006 indicated that there were approximately 15,000 pilgrims in 2006, fewer than in previous years, but heavy rain early that morning had been a deterrent. Two thirds of the pilgrims in 2006 were male. The pilgrims included participants from Sweden, Denmark, Germany, Australia, Brazil, the Netherlands, Italy, Latvia, India, Hungary and Canada. There were 3,500 first-time climbers .
Having celebrated the centenary of the building of the church on the summit, it was decided in 2005 to open the church every day during the summer, rather than only on holy days. Mass is celebrated in the church every last Sunday in July (Reek Sunday) and every 15 August. The church is opened by information guides.