Boris Johnson and Carrie Symonds have announced the birth of a "healthy baby boy at a London hospital earlier this morning".
Both mother and baby are doing very well, according their spokesman said.
First Minister Nicola Sturgeon responded to the happy news on Twitter.
She said: “Some good news - sending congratulations to Carrie and the PM. And wishing health and happiness to the wee one."
This is a breaking news story. More as we have it.