'Prince and Princess Michael of Kent are delighted to announce the engagement of their daughter Lady Gabriella Windsor to Mr Thomas Kingston,' the Palace said in a statement.
'The engagement took place in August; Mr Kingston proposed on the Isle of Sark.'
The wedding on May 18 is due to be a 'low key event' for royal standards.
According to People magazine, a Buckingham Palace source said it will be 'a private wedding for family and friends'.
The reception is due to be held at the same venue as Harry and Meghan, Frogmore House.
There is no word on whether Queen Elizabeth has RSVP'd to the prestigious event.
Seeing as the wedding is the day before the Duke and Duchess of Sussex's one-year anniversary (and presumably the couple will be battling soiled nappies and late-night crying), it is unknown if they will be attending either .