Beaufort Castle (Scottish Gaelic: Caisteal Duuaidh) is located near Beauly in Inverness-shire, northern Scotland. It is 1 mile (1.6 km) north of Kiltarlity, and 12 miles (19 km) west of Inverness. The present castle is a Baronial style mansion built in 1880, but incorporates older building work. There has been a castle on the site since the 12th century. Beaufort is the traditional seat of the Lords Lovat.
The earliest mention of the site, as Downie or Dounie Castle, occurs in the reign of Alexander I (1106–1124), when a siege took place. The original castle was built by the Byset family. The castle came into the hands of the Frasers in the late 13th century. English forces besieged the castle in 1303.
In the 1650s Dounie was attacked and burned by the forces of Oliver Cromwell during their invasion of Scotland.
The Fraser estates were inherited by Simon Fraser, 11th Lord Lovat (c.1667–1747), in 1699. Known as 'The Fox', Lovat became deeply involved in the Jacobite cause, which aimed to restore the deposed House of Stuart to the thrones of Scotland and England. Exiled to France, Lovat joined James Stuart, the Old Pretender, and converted to Catholicism. He attempted to recruit Scottish nobles to the cause, carrying messages to Scotland, but his dealings led to ten years imprisonment in France. Returning in 1714, he apparently renounced the Jacobite cause in return for possession of his estates. In the 1740s he commissioned William Adam to design a new house at Dounie. Adam's last work, the project only progressed to the supply of stonework to the site: construction never started since the Jacobite Rising of 1745 intervened. Lovat, changing allegiance again, supported the Jacobites, but was captured and executed after the Battle of Culloden. Dounie Castle was razed by the Duke of Cumberland, and the estate was declared forfeit.