Today, Princess Eugenie celebrates her 31st birthday. Princess Eugenie marks her 31st birthday, and her first as a mother, after she recently welcomed first son August to the world. Queen Elizabeth congratulated Princess Eugenie as she celebrates her 31st birthday. The Royal Family’s Instagram account shared a photo of Princess Eugenie at Royal Ascot in 2019 alongside the caption, "I wish Princess Eugenie a very happy birthday today!"