His statement was short and sweet, but summed it up perfectly.
Prince William said Monday that, "We could not be happier."
It's a boy, though his name has not been revealed.
An aide says William, 31, spent his first night as a father at St. Mary's Hospital in Paddington, London, with, Kate, 31, and their little newborn son.
Just after the official birth announcement was made, William's dad, Prince Charles, said he was "overjoyed" about being a grandfather, adding:
"Grandparenthood is a unique moment in anyone's life, as countless kind people have told me in recent months, so I am enormously proud and happy."
The wildly-anticipated birth of the young heir to the throne has been welcomed with an outpouring of love and support throughout the UK and world.
It's unclear when he'll be introduced to the world, but we can't wait!