The sweet black-and-white shot shows the Duke of Cambridge giving his youngest son, 20-month-old Louis, a kiss on the cheek.
George, 6, is sitting in a chair, wearing a zip-up jacket and shorts, while Charlotte, 4, is standing in between her brothers. She's wearing a puffy jacket over a dress and appears to have a backpack on, and her hands are placed gently on Louis' shoulders.
"?Merry Christmas! This photograph of The Duke of Cambridge, Prince George, Princess Charlotte and Prince Louis was taken by The Duchess of Cambridge in Norfolk earlier this year," Kensington Palace shared. "We wish all our followers a very happy and relaxing Christmas Day ⛄️."
It's set to be a big Christmas for William and Kate's oldest kids. Earlier this month, a royal source told ET that George and Charlotte are expected to accompany the royal family to Christmas service at Sandringham for the first time. The children have attended church in Berkshire before, but this would mark the first time they will have walked to St. Mary Magdalene Church with their parents.
For more on the Duke and Duchess of Cambridge's Christmas celebrations, check out the video below.