Katherine FitzGerald suo jure Viscountess Grandison (August 1660- 26 December 1725) was a wealthy Irish heiress being the only child of Sir John FitzGerald of Dromana County Waterford. She inherited the Dromana estate in 1664 upon the death of her father. She was married three times; firstly to John Le Poer 2nd Earl of Tyrone; secondly to Brigadier-General Hon.