The Duke and Duchess of Sussex are expecting their second child, a spokesperson for the couple has said.
Harry and Meghan are preparing to welcome a brother or sister for their son Archie Mountbatten-Windsor, who turned one last May.
A spokesperson for the couple said they were "overjoyed".
A Buckingham Palace spokesman said the Queen, Duke of Edinburgh, Prince of Wales and the rest of the Royal Family "are delighted and wish them well".
Harry and Meghan shared a black and white picture of themselves under a tree, with Harry resting his hand on Meghan's head as she cradles her bump.
Their child will be eighth in line to the throne.
Meghan's due date has not been revealed, but her bump appeared prominent in the photograph.
The news comes after the duchess said in November that she had suffered a miscarriage last July, writing in an article of feeling "an almost unbearable grief".
A spokesperson for the Duke and Duchess of Sussex said: "We can confirm that Archie is going to be a big brother.
"The Duke and Duchess of Sussex are overjoyed to be expecting their second child."
Misan Harriman, a friend of the Duke and Duchess of Sussex and the photographer who took the photo that accompanied their pregnancy announcement, tweeted: "Meg, I was there at your wedding to witness this love story begin, and my friend, I am honoured to capture it grow.
"Congratulations to The Duke and Duchess of Sussex on this joyous news!"