Duntulm Castle is a ruined ancient fortress near the village of Trotternish on the Isle of Skye, Scotland. It is believed to have been an Iron Age fort originally known as Dún Dhaibidh (David's Fort in Gaelic). In the late Viking period, it was fortified by the Norse who settled in the Outer Hebrides, and later by one of the clans that became the owners of the island, the Macleods of Skye.

In the early 17th century, Trotternish was under the control of the MacLeods' rivals in Skye, the MacDonalds of Sleat. They appear to have made several improvements to the castle, and it is possible that much of the structure recorded in the late 19th century, apart from the keep, dates from this period.

The MacDonalds abandoned the castle around 1730 in favour of nearby Monkstadt House and then Armadale Castle in Sleat. Some say this was after a nurse accidentally dropped the chief's young son from a castle window onto the cliffs. The ghost of the nurse, murdered in revenge, is still said to haunt the ruins, and the child's cries can be heard. Apparently, she is accompanied by the ghost of Hugh MacDonald, who conspired against the rightful chief in the 17th century and starved to death in the dungeons of Duntulm.

The MacDonalds of Sleat were created baronets in 1625, and some of their heirs fought in England in 1651 and fought in the Jacobite risings of 1689 and 1715, which sought to restore Scottish independence.

Earlier, Hugh MacDonald was imprisoned and starved to death in a dungeon at Duntulm after attempting to seize the lands of Trotternish by murdering his kinsmen, having been captured after fleeing to Dun an Sticer in North Uist. He was given only salt beef and no water, and died delirious: his ghostly moans are also said to be heard in the ruins of Duntulm.

Among the early lords of the castle is a Donald Gorm who was succeeded by his son, also called Donald Gorm, who was succeeded by his son, also called Donald Gorm. He, in turn, was succeeded by his nephew, another Donald Gorm. From Duntulm you can reach Caisteal Uisdean (Hugh's Castle), a few miles south of Uig. Hugh was a cousin of one of the Donald Gorms and built his castle without doors or windows, with the only access being through the roof.

When the castle was finished, Hugh wrote to his cousin inviting him to the inauguration. He also wrote to Martin, with whom he arranged to have Donald murdered during his visit. But Hugh confused the two letters and exchanged them. Learning of his cousin's plan, Donald Gorm sent his armies to besiege Caisteal Uisdean.

Furthermore, this Donald Gorm was married to Margaret, sister of Rory Mór MacLeod of Dunvegan. Margaret had lost an eye and Donald Gorm took a dislike to her for it. Finally, he sent her back to her brother on a one-eyed horse, accompanied by a one-eyed man and a one-eyed dog. And this insult gave rise to the Cogadh na Cailliche Caime (the war of the one-eyed woman).