The Prince and Princess of Wales posted the photograph on their official social-media accounts with a brief message wishing their eldest son a happy 13th birthday. In the portrait, George wears a dark suit with an open-collar white shirt, presenting a more formal look than those seen in several of his previous birthday photographs.
George was born on July 22, 2013, at St. Mary's Hospital in London. As the eldest child of William and Catherine, he is second in line to the British throne, immediately behind his father.
The new image continues a tradition established by the Wales family, which has regularly released photographs to mark the birthdays of George and his younger siblings, Princess Charlotte and Prince Louis. This year's portrait quickly attracted attention online, with royal watchers commenting on how much George has grown and comparing his appearance with photographs of Prince William at the same age.
George's birthday comes shortly before another major transition. Kensington Palace confirmed in June that he will attend Eton College beginning in September, following in the footsteps of his father and his uncle, Prince Harry.
"Kensington Palace can confirm that Prince George will attend Eton College from this September," a palace spokesperson said when the decision was announced.
George currently attends Lambrook School in Berkshire alongside Charlotte and Louis. His move to Eton will mark the first time in several years that he will attend a different school from his younger siblings.
The 13-year-old has continued to make occasional public appearances with his family. Most recently, he joined William and Catherine at the Wimbledon men's singles final and has also appeared at major royal occasions, including Trooping the Colour.
His parents have generally limited their children's public schedules while gradually introducing them to official events. No verified information has been released about George's private birthday celebration, including whether the family held a party or who may have attended.
George's birthday follows another royal milestone in July, with Queen Camilla celebrating her 79th birthday on July 17. However, the release of George's annual portrait remains one of the most closely watched Wales family traditions, particularly as the future king enters his teenage years.
The Palace has not provided further details about George's birthday activities or private life.