Jamie took to Instagram to share the good news, along with a photo of his adorable baby boy, writing, "And then this just happened guys!! IT'S A BABY BOY!! Everyone in the Oliver family is very surprised and beyond happy."
"He arrived safely, [Jools] was really really amazing, unbelievably composed, natural birth and my two eldest girls got to come in at the very end as the baby was born which was amazing to witness," Jamie continued. "Very very emotional."
The 41-year-old Food Revolution star revealed that his son was born weighing 8 lbs -- noting, "That's 16 packs of butter for you bakers out there" -- and that they have not yet chosen a name for the newest addition to their family.
Jools shared a heartwarming photo from her hospital bed, showing her baby boy nursing. She captioned the sweet snapshot, "We are so very happy, blessed, grateful and totally in love all over again."
Their newborn son joins the Olivers' four other children, including 5-year-old son Buddy Bear Maurice, 7-year-old daughter Petal Blossom Rainbow, 13-year-old daughter Daisy Boo Pamela and 14-year-old daughter Poppy Honey Rosie.
According to Jools, the couple's two eldest daughters were actually the ones to cut the umbilical cord this time around.