Full House star John Stamos has officially become a dad!
Stamos, 54, took to Instagram Sunday to announce that he and his wife Caitlin McHugh are now proud parents to a little boy.
The actor revealed they have chosen to name their son Billy, after John's father.
John shared a sweet black-and-white snap of the tiny newborn lying on his dad's chest.
"From now on, the best part of me will always be my wife and my son," John captioned the touching post. "Welcome Billy Stamos (named after my father)."
Of course, fans were over the moon for John and Caitlin.
One person commented: "Congratulations to you and your beautiful wife! Baby Billy clearly has daddy’s hair!" while another gushed: "Welcome to the World, Billy!"
John and Caitlin announced they were expecting their first child together back in December.
John admitted at the time that he was thrilled to become a dad for the first time at 54.
The former General Hospital star spoke about the exciting news to PEOPLE magazine at the time.
John admitted he wasn't ready for fatherhood until now.
"Clearly I had to do some work on myself, first. I have a youthful thing," he continued. "People say, 'Oh, you look young.' You'll start believing you're gonna live to be 150. And then you wake up and go, 'No, man, this is it. This is not a rehearsal.'"
Stamos said he'll be a "fun dad" because he's been "practicing for a long time."
Their new arrival comes shortly after Stamos and 31-year-old Caitlin tied the knot on Feb. 3, after two and a half years together.
The couple exchanged their vows in a beautiful ceremony at The Little Brown Church in Studio City, Los Angeles.
Following the ceremony, the reception was held at Stamos' home in Beverly Hills.
While still adjusting to life as newlyweds, the couple are now adjusting to life as new parents!
Congratulations to John and Caitlin!