Richard Fitzwilliams’ father, Major Robert Fitzwilliams, TD, was a business executive who served in World War 11 (Royal Artillery, mentioned in despatches, Tobruk 1942) and was a keen genealogist. His father was Duncan Fitzwilliams, CMG, F.R.C.S. who was Consultant Surgeon to St Marys, London. His mother was Mary Elizabeth Filley of Massachusetts, USA.

Richard Fitzwilliams’ mother was Natalie Fitzwilliams, the figurative artist, who served at the Admiralty during World War 11. Her father was Colonel George Mardall, OBE, who served with the Natal Mounted Police.

Richard Fitzwilliams’ great-great-great-great grandfather was Edward Hall, the 18th Century apothecary and Secretary to the Whig Club of which he was also a founder. The family pedigree is included under Fitzwilliams of Cilgwyn in Burkes Landed Gentry (Wales and the North West) 2006. Collaterals of this family included Robert Mylne, the architect of Blackfriars Bridge and Surveyor to St Pauls Cathedral, the controversial Captain (later Vice-Admiral) William Bligh of the Bounty, through the Campbells and Admiral Richard Brathwaite through whom the property of Cilgwyn came into the family.

Richard Fitzwilliams married Gillian Savill, who worked for the BBC World Service in 1981. The marriage ended in divorce in 1995.