The Duchess can be seen smiling broadly as she holds baby Louis, while three-year-old Charlotte and five-year-old George hold on to their father.
At the same time, Harry and Meghan, the Duke and Duchess of Sussex, released their own Christmas card that shows the pair embracing on their wedding night in May.
The never before seen shot, which shows the newlyweds with their arms around each other as they watch a fireworks display, was taken in the grounds of Frogmore House, Windsor.
Harry and Meghan will soon take up permanent residence in nearby Frogmore Cottage as they prepare for the arrival of their first child, who will be seventh in line to the British throne, in the spring of 2019.
William and Harry’s father Prince Charles opted for a romantic shot alongside his wife, Camilla.
The cards are part of Christmas tradition for the royal family, which usually spends the holiday period at Sandringham, the Queen’s country estate in rural Norfolk, around 100 miles north of London.
The family arrives on Christmas Eve for afternoon tea and a black-tie dinner, along with the opening of presents. After breakfast on Christmas morning, they attend a church service followed by a country walk and games.