Matt Porteous revealed as Royal Photographer.
The portraits were taken by photographer Matt in July, at the home of the Duke and Duchess of Cambridge, in Norfolk.
A spokesman for Kensington Palace said:
"The Duke and Duchess hope that people will enjoy seeing these new photographs. They would like to thank everyone for all lovely messages they have received as Prince George celebrates his third birthday."
Photographer Matt Porteous said:
"I really enjoyed the opportunity to take these photographs of Prince George. It was a very relaxed and enjoyable atmosphere. I'm honoured that they have decided to share these images with the public to mark his third birthday."
Matt is a Director of Studio M, an award winning creative studio that specializes in portrait/commercial photography and film, based on the island of Jersey.
The relationships of the founding creatives Max, Googsi and Matt is the hallmark of their success. They have established an impressive name for themselves in the fields of sports, travel, lifestyle and ocean culture.