Houses in bold are in Mark Bence-Jones

Jackson Hall (see Coleraine: The Manor House)

Jamesbrook, Ballinacurra, Co Cork  http://aguidetoirishcountryhouses.com/2024/12/31/jamesbrook-ballinacurra-co-cork/

Jamestown (or Magheracross), County Fermanagh 

Jamestown, Co Laois https://aguidetoirishcountryhouses.com/2025/03/17/jamestown-co-laois/

Jamestown, Drumsna, Co Leitrim https://aguidetoirishcountryhouses.com/2025/03/19/jamestown-drumsna-co-leitrim/

Jamestown Court, Castletown Geoghegan, Co Westmeath https://aguidetoirishcountryhouses.com/2026/02/13/jamestown-court-castletown-geoghegan-co-westmeath/

Janeville House (or Ballybrommell House), Co Carlow https://aguidetoirishcountryhouses.com/2024/11/16/janeville-house-or-ballybrommell-house-co-carlow-2/

Jenkinstown House, Ballyragget, County Kilkenny – ‘lost’ https://aguidetoirishcountryhouses.com/2024/10/25/jenkinstown-house-ballyragget-county-kilkenny/

Jenkinstown House, County Meath 

Jigginstown House, Naas, Co Kildare https://aguidetoirishcountryhouses.com/2025/03/05/jigginstown-house-naas-co-kildare/

John’s Mall, Birr, County Offaly https://aguidetoirishcountryhouses.com/2025/04/20/johns-mall-birr-co-offaly-r42hk12/

Johnsbrook, Kells, Co Meath https://aguidetoirishcountryhouses.com/2024/10/29/johnsbrook-kells-co-meath/

Johnstown Castle and Gardens, Murntown, Wexford – open to public https://aguidetoirishcountryhouses.com/2023/09/30/a-heritage-trust-property-johnstown-castle-county-wexford/

Johnstown House, Carlow, Co Carlow https://aguidetoirishcountryhouses.com/2024/11/09/johnstown-house-carlow-co-carlow/

Johnstown, Enfield, Co Meath – hotel https://aguidetoirishcountryhouses.com/2024/10/17/johnstown-estate-enfield-co-meath-hotel/

Johnstown (formerly Peterfield), Puckaun, Co Tipperary https://aguidetoirishcountryhouses.com/2025/02/21/johnstown-formerly-peterfield-puckaun-co-tipperary/

Johnstown Kennedy House, Co Dublin – demolished http://aguidetoirishcountryhouses.com/2025/01/13/johnstown-kennedy-house-co-dublin-demolished/

Jonestown House, Co Offaly 

Jubilee Hall, Ballyman Road, Ballyman, Old Connaught, Co Dublin 

Julianstown House, Julianstown, Co Meath 

Julianstown House, Nobber, County Meath