Mariga Guinness (born Hermione Maria-Gabrielle von Urach; 21 September 1932 – 8 May 1989) was an architectural conservationist and socialite, and co-founder of the Irish Georgian Society.
Urach was returned to Europe, where she was brought up by her godmother, Hermione Ramsden, in Surrey and Norway, and educated by as many as seventeen governesses, with brief spells in boarding schools.
In 1967 they bought Castletown House, also in County Kildare, with a plan to restore it, and make it a base for the Irish Georgian Society.
She later moved to Glenarm, County Antrim to live with Hugh O'Neill, and when that relationship ended, she returned to Leixlip Castle, but a divorce was finalised in 1981.
Marina is a patron of the arts and of Irish musicians including Glen Hansard, Damien Rice, and the band Kíla.
Marina has three children of her own: Patrick (by Stewart Copeland of The Police), Violet (by photographer Perry Ogden), and Finbar (by record producer Denny Cordell).