The mountain has a pyramid-shaped peak and overlooks Clew Bay, rising above the village of Murrisk, several kilometres from Westport.

It was the focus of a prehistoric ritual landscape, and later became associated with Saint Patrick, who is said to have spent forty days fasting on the summit.

[10] Archaeologist Christiaan Corlett writes that the large number of prehistoric monuments surrounding and oriented towards Croagh Patrick "suggests that the mountain has been a local spiritual inspiration since at least the Neolithic, and during the Bronze Age became the focus of an extensive ritual landscape".

[11] A short distance east of the mountain lies the Boheh Stone, an outcrop covered with ancient rock art.

[13] Archaeological surveying found remains of an enclosure encircling the mountaintop and dozens of circular huts abutting it, which showed evidence of Bronze Age date.

[14] Tírechán, a native of Connacht, wrote in the 7th century that Saint Patrick spent forty days on the mountain, like Moses on Mount Sinai.

Patrick ended his fast when God gave him the right to judge all the Irish at the Last Judgement, and agreed to spare the land from the final desolation.

[18] There is reference to a "Teampall Phádraig" (Patrick's Temple) from AD 824, when the Archbishops of Armagh and Tuam disagreed as to who had jurisdiction on the site.

[27] The Tochar Phadraig was revived and reopened as a cross-country pilgrimage tourist trail by Pilgrim Paths of Ireland; the 30-kilometre route takes about ten hours.

[27] Local people and organisations point out that the large number of climbers – as many as 40,000 per year – have damaged the mountain by causing erosion which makes the climb more dangerous.