Mangerton or Mangerton Mountain, at 838 metres (2,749 ft), is the 19th-highest peak in Ireland on the Arderin list, and the 26th–highest mountain according to the Vandeleur-Lynam list. Mangerton is the tallest mountain in the Mangerton Mountain Group, also called the Mangerton Mountains or the Mountains of East Kerry, a range that includes five other major mountains that have a height above 2,000 feet (610 m). Mangerton's western slopes lie within the Killarney National Park. On Mangerton's north-western face lies a deep corrie lake called the Devil's Punchbowl, which is a popular scenic destination for hill walkers; although the mountain is often overlooked by walkers due to the proximity of its more scenic and accessible neighbour, Torc Mountain. The far northern slopes of Mangerton was the site of an important 13th-century battle between the Mac Cárthaigh, and the FitzGeralds, known as the "Tooreencormick battle site".

In these lists of mountains in Ireland, those within Northern Ireland, or on the Republic of Ireland – United Kingdom border, are marked with an asterisk, while the rest are within the Republic of Ireland. Where mountains are ranked by height, the definition of the topographical prominence used to classify the mountain, is noted. In British definitions, a height of 600 metres (1,969 ft) is required for a mountain, whereas in Ireland, a lower threshold of 500 metres (1,640 ft) is sometimes advocated.