It's going to be one of the most closely watched baby bumps in the world, and it's of particular significance to Canada.
As news of a royal pregnancy was announced by St. James Palace in England on Monday, Canadians in particular were quick to offer their congratulations to Prince William and his wife, Kate.
Both the prime minister and the Governor General conveyed their good wishes on Canada's behalf, while many Canucks took to the Internet to express their individual delight at the news.
"I love the royals, so it was pretty exciting," said Toronto resident Alanna Glicksman, who has followed news of the royal couple since they dated in university and tweeted a photograph of William as a baby soon after the pregnancy was announced.
"Their whole story was really nice to watch it play out. It's not so much of a monarchy thing, it's just how they are. They seem so relatable as people."
The 25-year-old Toronto resident said being a Canadian, however, enhanced her interest in the royal couple to an extent.
"It's nice to feel like you're part of it," she said. "As Canadians it's nice to feel like we still have our ties to the monarchy."
Indeed, some observers suggest news of a royal baby is particularly significant for Canadians since the child â€” regardless of whether it is a boy or a girl â€” will be in line to become Canada's head of state one day.
The leaders of Britain and the 15 former colonies that have the monarch as their head of state agreed in 2011 to new rules which give females equal status with males in the order of succession. Although none of the countries have officially legislated the change yet, the British Cabinet Office has confirmed it as a de-facto rule.
"Royal births in the past have often been an impetus for various kinds of reform...This event is very significant in terms of symbolizing the monarchy's future," said Carolyn Harris, a royal historian based in Toronto.
"There's going to be huge interest on how they will raise their child."