He was recruited by Kensington Palace as deputy interactions secretary in December 2018, offering PR recommendations to both the Cambridges and the Duke and Duchess of Sussex.
His departure comes after it emerged that Julian Payne, Prince Charless spin doctor of five years, is leaving Clarence House to join Edelman, the communications company.
Then after Mr Case, who is now the UKs Cabinet Secretary, was seconded to Downing Street, he became the Dukes personal secretary and head of the royal family.
Having invested four years working as an economist in the Treasury under George Osborne, Mr Jones signed up with the Department for Exiting in the European Union in 2016 before signing up with the Europe System 2 years later.
Earlier on Tuesday, Mr Jones was called in court as being one of 4 royal aides who will be asked to offer evidence in Meghans case against Associated Newspapers over the publication of a letter she composed to her father, Thomas Markle Snr..
Within three months, as tensions started to develop in between the couples, he was promoted to William and Kates interactions secretary..