The annual charity gala, which is now in its fourth year, benefits a foundation for terminally ill children and a trust for injured soldiers.
Prince George’s 29-year-old uncle looked sleek and chic in a tuxedo as he made his way inside the gala.
Meanwhile, Middleton, 30, who arrived separately with beau Nico Jackson, stunned in a pleated saffron skirt and crisscross black bodice.
The couple were the guests of honor at the event.
Other A-list attendees included Harry’s pregnant cousin Zara Phillips, as well as track-and-field Olympian Jessica Ennis and soprano star Katherine Jenkins.