A birthday photo and video have been released of Prince George as the young royal celebrates turning into a teenager.

George, who reached his 13th birthday on Wednesday, was pictured at Kensington Palace in a portrait captured after he returned from Trooping the Colour on June.

The image was shared on the Prince and Princess of Wales’ social media, alongside the message “Happy 13th Birthday, George!” followed by a party popper emoji.

It was taken by Matt Porteous, William and Kate’s go-to photographer for family celebrations.

Future king George is heading to a new school in September following in his father’s footsteps by attending the prestigious Eton College, close to his Windsor home.

He was last seen out with his family when he and 11-year-old Princess Charlotte joined William and Kate in the royal box at Wimbledon.

British wildcard Arthur Fery invited the siblings to play tennis with him when they chatted while attending the men’s singles final.

George, Charlotte and their younger brother Prince Louis will now be enjoying their summer holidays.

George has finished his time at Lambrook School, the private co-ed prep school in Berkshire where he occasionally boarded, ready for his transition to boys-only Eton, where fees are more than Stg65,000 ($124,000) a year.

Prince George Alexander Louis was born in the private Lindo Wing of St Mary’s Hospital, Paddington, London, on July 22, 2013.

—AAP