Kilchurn Castle is a ruined 15th and 17th century structure on a rocky peninsula at the northeastern end of Loch Awe, in Argyll and Bute, Scotland. Kilchurn Castle was built in about 1450 by Sir Colin Campbell, first Lord of Glenorchy, as a five storey tower house with a courtyard defended by an outer wall. By about 1500 an additional range and a hall had been added to the south side of the castle. Further buildings went up during the 16th and 17th centuries. Kilchurn was on a small island in Loch Awe scarcely larger than the castle itself, although it is now connected to the mainland as the water level was altered in 1817. The castle would have been accessed via an underwater or low lying causeway.
Towards the end of the 16th century the Clan MacGregor of Glenstrae were occupying the castle. Once owning the lands of Glenorchy during the 14th century, until they passed through marriage to the Campbells, the MacGregors were appointed keepers to Kilchurn Castle as the Campbells spent much of their time at Fincharn. This arrangement lasted until the very early part of the 17th century, when a violent feud between the two families brought it to an end and the Campbells retook possession.
In 1681, Sir John Campbell of Glenorchy was made 1st Earl of Breadalbane. To take advantage of the turbulence of the times, he converted Kilchurn into a modern barracks, capable of housing 200 troops. His main addition was the three storey L-shaped block along the north side.