The 40-year-old singer and his 28-year-old wife Luisana Lopilato are already parents to two-year-old Noah, and announced their new arrival on Twitter, reported New York Daily News.
Alongside a picture of him and Luisana with their little boy, Michael wrote: "And then there were four. Introducing Noah's little brother Elias."
In the snap, both Michael and Luisana are seen beaming for the camera, while little Elias curls up to his mother.