In a release issued Monday, Kensington Palace said the photographs were taken by Michael Middleton, Kate's father, in early August in the garden of the Middleton family home in Bucklebury, Berkshire, England.
Prince George was born July 22 in a London hospital. He is third in line to the throne after Princes Charles and William.
William has also described his son as a "little bit of a rascal."
In an excerpt from his first official interview since the birth of George, William told CNN his son and his wife are both doing well, adding that she is doing a "fantastic job."
"He’s a little bit of a rascal, let’s put it that way," William said in his first official interview since his son's birth. "He either reminds me of my brother or me when I was younger — I’m not sure — but he’s doing very well at the moment."
CNN plans to air the full interview on Sept. 15.