Gylen Castle is a ruined castle on the Scottish Hebridean island of Kerrera. It lies on a rocky headland on the southwest shore of the island on the coast of the Firth of Lorne. The nearest town is six kilometers north-east of Oban on the mainland. 1971 Gylen Castle was included in the British lists of monuments in category A.
Gylen Castle was the seat of the Clan MacDougall. The building was built in the 16th century by Duncan MacDougall of MacDougall and Cuillin Hills and completed after reported variously as either 1582 or 1587. In 1647 it came to the siege of the castle, in consequence of which the Covenanter burned down the building under General Leslie and the inhabitants killed. Gylen Castle was then inhabited at no time more and fell into disrepair.
In 1913, minor repairs to the building were carried out to prevent the collapse. In 1972, Leslie Grahame MacDougall at the monument protection authorities an application for funding for the restoration of Gylen Castle and obtained the provision of £ 200,000. In addition, an amount of £ 300,000 was collected through a fundraising campaign among the clan members. With the restoration work was started in 1993. In February 2002, was a thorough archaeological survey of the ruins, the outbuildings and the environment. After completion of construction Gylen Castle was finally opened on 12 May 2006 for visitors.