The second-in-line to the throne and the former Kate Middleton will be at the Middleton residence in Bucklebury, a village west of London, a spokesman for St James's Palace said.
"The Duke and Duchess of Cambridge will spend Christmas Day privately with the Middleton family," the spokesman said, using the official titles given to the couple after they married in April 2011.
They plan to visit the queen's Sandringham Estate in Norfolk, eastern England, later in the festive season, the palace said. The monarch and her husband Prince Philip were understood to have approved the couple's decision.
The Cambridges spent Christmas at Sandringham last year, at a time when Philip was in hospital after undergoing a heart procedure.
It will be the first Christmas since William and Catherine, both 30, announced that they are expecting their first child together.
Catherine spent several days in hospital in London earlier this month with severe morning sickness.
Her father Michael and mother Carole, who run a party supplies business, and her sister Pippa and brother James are all expected to be spending Christmas with Catherine and William.
Pippa - who became famous for the figure-hugging dress she wore at the royal wedding - said recently that her father Michael often donned fancy dress for Christmas.
"Home is, happily, where I'll be this year," Pippa wrote in The Spectator, a political weekly. "The Middletons' Christmas should be blissfully calm. We're good at keeping each other's spirits up."
She said Michael Middleton "buys a new costume each year and typically gets a bit carried away - a couple of Christmases ago, he appeared in an inflatable sumo outfit."
Separately on Friday, British police said they have sent a file to prosecutors relating to a hoax call by two Australian radio presenters to the hospital treating Catherine, after which a nurse died in an apparent suicide.
Nurse Jacintha Saldanha was buried earlier this week in her native India.