Benbreen at 691 metres (2,267 ft), is the 100th–highest peak in Ireland on the Arderin scale, and the 122nd–highest peak on the Vandeleur-Lynam scale. Benbreen lies in the southern end of the Twelve Bens mountain range in the Connemara National Park in County Galway, Ireland. Benbreen is the 4th-tallest mountain of the Twelve Bens range, after Benbaun 729 metres (2,392 ft), Bencorr 711 metres (2,333 ft), and Bencollaghduff 696 metres (2,283 ft). Benbreen's profile is of a "high narrow rocky ridge with several summits", than a typical "peaked mountain".

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.