While on the balcony, Meghan was spotted doting on her new grandmother-in-law, Queen Elizabeth.
For the royal event, the duchess wore an Audrey Hepburn-inspired look, wearing a bespoke Dior black dress with a boatneck.
While on the balcony, the Duchess of Sussex also enjoyed a laugh with husband Harry, Prince William and Kate Middleton.
Later in the day, Meghan and Harry touched down in Dublin for a two-day Ireland tour.
Meghan stunned in a green dress, which you can see here.