Howth Castle, Medieval castle in Howth, Ireland

Howth Castle is a residence near Dublin whose buildings combine elements from different periods of construction and design spanning over 700 years. The structure shows medieval foundations, Gothic details, Georgian additions, and early 20th-century modifications that Edwin Lutyens designed for the family.

The St Lawrence family held Howth as feudal lords from 1179/1180, and their first castle was a timber structure on Tower Hill above Balscadden Bay. A new wooden castle was built on the present site around 1235, and the oldest surviving stone parts, the keep and gate tower, date from around 1450. Edwin Lutyens restyled the castle in 1911; the family sold it to Tetrarch in 2019.

The castle's name and estate recall the St Lawrence family, feudal lords of Howth from 1179/1180 and later Barons and Earls of Howth. A legend tells that Gráinne O'Malley abducted the heir in 1576 after the gates were closed at dinner; the family then promised to keep the gates open to unexpected visitors and set an extra plate at every meal. The castle interiors were sold at auction in 2021, so they are not open to visitors.

The castle interiors are not open to the public; tours have only been occasional, and the furniture and contents were auctioned in 2021. The estate around it holds golf courses, a hotel, gardens and rhododendron walks, plus paths toward Howth Head's cliff walks and views of Ireland's Eye. The grounds are extensive, so allow time on foot.

Within the grounds stands an ancient stone tomb called Aideen's Grave dating back thousands of years to prehistoric times. This archaeological remnant connects the location to a much older past that existed long before the castle was built.