Proud parents William and Kate showed off their new baby on the steps outside the Lindo Wing just after 3AM Australian time, with the beaming couple thrilled to show their second son.
As Kate - wearing a red Jenny Packham dress - held the new arrival William said "we're very happy'
They went back inside and reemerged with William holding the baby in a carry cot.
After putting him in the back of the Range Rover he said "Very happy but we've now got thrice the worry! At least we didn't keep you waiting.'
The Duke and Duchess of Cambridge's son weighed in at 8lbs and 7oz, Kensington Palace confirmed via Twitter.