St. Helen's is a period house built in the early 1750s and located in Booterstown, County Dublin, Ireland.

The house was originally called Seamount and an entry in the Registry of Deeds shows on 20 June 1754 an agreement between the first owner Thomas Cooley and Richard Viscount Fitzwilliam to let "all that one acre of land plantation entered in and on the west to the high road leading from Dublin to Wicklow".

[1] It is understood that Thomas Cooley, noted as being a Dublin barrister and MP of Duleek, was finishing the house and some outbuildings.

[1] The house was sold in 1795[1] to Robert Alexander, an early patron and churchwarden of St. Philip and St. James Church, Booterstown.

[1] In 1899, the next owner, Sir John Nutting, improved the house greatly spending thousands of pounds.

[2] A repoussé copper frieze depicting ships and galleons made around 1900 by James Smithies of Manchester, was added to the dining room.

[2] In 1990 Seán Dunne's property company, Berland Homes, built the houses of St. Helen's Wood.

[5] The Corporation of Dún Laoghaire bought 9 acres for road reservation[2] with the intention of using it as part of the then proposed Eastern Bypass[6] with the M50 motorway.

This would see the road enter from the UCD side of Fosters Avenue and transit through the southwest to the northeast of the property and make its way to the Booterstown marsh.

[7] In 1996 Shannon Homes paid £5.6m for 13.69 acres to the rear northeast of the house and built the Seamount apartments.

[2] Located in the front gardens is the sculpture called Continuum by Linda Brunker, commissioned by the Cosgrave Property Group and unveiled in 1998.