'The engagement took place in August,' the Palace revealed, adding that Gabriella's partner Tom proposed to his girlfriend of three years on the Isle of Sark, in the English Channel, off the coast of France.
No further details have been announced, but it's believed the event will take place between March and June next year.
Lady Gabriella, who is known as 'Ella' to her family and friends, doesn’t have a royal profile quite like her cousin Prince Charles, however she often attends big events.
The 51st in-line-to-the-throne is a frequent guest at Christmas festivities with the Queen in Sandringham and she's also taken up prime position on the Buckingham Palace balcony during significant occasions, including Trooping the Colour.
Congratulations to the couple!