Ballymoyer House, now demolished, was an early 19th-century country house which stood in its own 7000 acre demesne in the townland of Ballintemple, some 5 km (3 miles) north east of Newtownhamilton, County Armagh, Northern Ireland.
The house was a classical 7-bay three-storey building with a stucco facade and a collonaded porch which had been linked by corridors to a previous building. The older part housed a library, the smaller bedrooms and servants' quarters and the newer part the main bedrooms, drawing room and dining room.
The newer building was constructed in 1778 for Sir Walter Synnot of a well-to-do family of linen merchants who had leased the land from the See of Armagh. He and his son Marcus considerably improved the landscape to the extent that it was described in the Parliamentary Gazetter of 1844 in the following terms: "The mansion built by Sir Walter Synnot and the demesne attached to it is laid out and planted in a tasteful style. Three mountain streams after debouching from the glens of their upper course, unite in the lawn and form a scene both beautiful and romantic". By 1838 the family had bought the land. Sir Walter was High Sheriff of Armagh for 1783 and married Jane Seton. Marcus was High Sheriff in 1830 and died in 1835, succeeded by his son, also Marcus (High Sheriff in 1852). Marcus junior died childless in 1874 and the estate passed to his younger brother Mark Seton Synnot (High Sheriff in 1876). Mark Seton's son, also Mark Seton, a captain in the Armagh Light Infantry, died unmarried in 1901, whereby the estate devolved to his eldest sister Mary Susanna.
Mary Susanna had married in 1868 Major-General Arthur FitzRoy Hart, who had then adopted the surname Hart-Synnot. Their son, Brigadier-General Arthur Henry Seton Hart-Synnot inherited the demesne on his father's death in 1910 and sold portions of it to his tenants prior to 1919 under the Land Acts. He demolished the house c.1918 after it had been damaged by military accommodation during the First World War and donated the remaining land to the National Trust in 1938.
The estate is now open to the public.
- "Ballymoyer House". Lord Belmont In Northern Ireland. Retrieved 2013-01-05.
- "Ballymoyer Estate". Lord Belmont In Northern Ireland. Retrieved 2013-01-05.
- Burke, Bernard. A genealogical and heraldic history of the landed gentry of Ireland (1912). p. 674.