Photographed on the balcony of Buckingham Palace, the event celebrates Queen Elizabeth II’s birthday.
The Duke and Duchess of Cambridge – who left their newborn daughter Princess Charlotte indoors – looked every bit the royal couple at the annual event.
The Duchess, 33, wore a silk, ice blue and white, floral Catherine Walker Astrid coat dress, paired with a blonde-colored Lock & Co’s Marisabel hat with curled feathers.
Meanwhile, Prince William was decked out in a scarlet red military dress uniform and Prince George stole the show by making his first public appearance on the Buckingham Palace balcony.
The Duke and Duchess were joined by other members of the royal family, including Prince Harry, 30, Prince Charles, 66, and Queen Elizabeth II.
The Duchess rode in an Ascot Landau open-air horse-drawn carriage with her MIL, Camilla, Duchess of Cornwall, 67.
Last week, Kensington Palace released four official photos of Prince George and Princess Charlotte.