The Brit was at his wife Jools' side as she gave birth to little Buddy on Wednesday (15Sep10), and he announced the happy news on his Twitter.com page, writing, "It's a baby boy guys !!! im shock (sic), were all very happy, mum was amazing and both are well and happy!
"Mr Buddy Oliver... full name to come from mum.... big love."
The couple is already parents to three girls; Poppy Honey, Daisy Boo and Petal Blossom Rainbow.
The Olivers wed in June 2000.