The superstar couple broke the big news on Kardashian's app in a short and sweet post alongside a photograph of them holding hands.
The announcement read: "KANYE AND I WELCOME OUR BABY BOY!
"Kim Kardashian West and Kanye West welcomed the arrival of their son this morning. Mother and son are doing well."
The reality TV star gave birth three weeks early, after suffering a difficult pregnancy. Her daughter North West was delivered five weeks early in 2013.
Sadly the couple didn't share the name of their little bundle or joy, but we can't wait to hear it.
Congratulations to the couple and to North West, on the arrival of her new baby brother.