Watch Michael’s cute-as-a-button son announce the news in an adorable Facebook video.
The couple - whose son Noah will turn two in August - revealed the news in a sweet video posted on Michael's Facebook page.
The clip, which features a soundtrack of Britney Spears' song 'Oops I Did It Again', shows Noah point to his mother's stomach and say "baby" after Michael asks him "who's in there?"
Along with revealing the happy news, the video will also reassure fans that Noah has recovered after being taken to hospital last week.
Noah is believed to have been injured by scalding water at their home and taken to Hospital Aleman in Buenos Aires, Argentina, by his mother, model and actress Luisana, 28.
But Canadian crooner Michael revealed on Instagram five days ago that the tot was home just in time for Canada Day.
Posting a picture of footprints in the sand belonging to himself, Luisana and Noah, Michael wrote: "We want to thank you for the love and concern you have shown for our little guy through this difficult time. I'm happy to report that he is home, happy and healthy on what turned out to be a great Canada day. #love #grateful #family"
Previous reports suggested Michael, 39, was out of the country when the couple's only child was injured in the accident but he has since been reunited with his family.
thank you for the love and concern you have shown for our little guy. He's home healthy and happy. Love you all pic.twitter.com/99oVxjWr0G— Michael Bublé (@michaelbuble) July 2, 2015
Story: ©BANG Showbiz. Photo: Akira M. Shinsaku/PHOTOC/SIPA/REX