Bencullagh is a Hewitt of 634 m in Galway. All four of its nearest neighbours are higher, up to Benbaun at 729 m.
Of the 13 register hills in Galway, it has the smallest drop. All four of its nearest neighbours lie to the east, so it stands at the western edge of its group. It is the lowest of the seven register hills in the The Twelve Bens region, where Benbaun is highest. On the Hewitts height ladder it sits between Mullaghclogha (635 m) and Tarrenhendre (633.8 m). Its other name is An Chailleach.
