Manderley Castle, formerly "Victoria Castle" and "Ayesha Castle", is a large castellated Irish mansion built in Victorian style, in Killiney, County Dublin, Ireland. It is currently owned by Enya.

From the roof of the crenellated turret of the Castle, one may look beyond the Irish coast as far eastward as Wales. The building is surrounded by 14,000 m2 (3.5 acres) of manicured garden threaded with sylvan walks. A secret tunnel at the bottom of the garden originally gave access to Killiney beach but now is sealed off.

Judge Robert Warren built Victoria Castle in 1840 to commemorate Queen Victoria's accession to the throne. The interior was gutted by fire in 1928, then magnificently restored by Sir Thomas Power of the celebrated whiskey family; he renamed the mansion "Ayesha Castle", after the goddess who rose from the flames in Rider Haggard's novel She. In 1995, the Aylmer family decided to turn Ayesha Castle into a place of tourist interest, converting existing stables to a ground floor apartment and a first floor craft room". The Stable Gallery was established there, and many artists displayed their pictures.

Irish musician Enya bought the Castle in 1997 for €3.8 million, reportedly outbidding Michael Flatley, who also viewed the house. Out of her love for Daphne du Maurier's Rebecca, Enya renamed the Castle "Manderley" for the fictional house that plays a central role in the 1938 novel.

Because of serious threats from stalkers, Enya substantially reinforced the security of the Castle, installing new solid timber entrance gates, raising the surrounding 41 metres (135 ft) of stone wall to more than 2.7 metres (9 ft), and placing 1.2 metres (4 ft) railings atop some sections.Despite these changes, around mid-August 2005, there were two separate security breaches while Enya was at the Castle .