The actor and dancer and his wife Shelby Rabara are expecting their first child.
Shum shared the happy news on Instagram on Sunday, November 11, posting a shot of himself hiding behind his shocked wife with his hands on her baby bump.
Rabara, an actress and former Los Angeles Lakers cheerleader, also posted shots on social media.
The couple wed in 2015.
The baby news comes just days after Rabara took to Instagram to mark the 12th anniversary of the pair's first date.