The Fuller House star announced the news on Instagram, revealing he and wife Caitlin McHugh have welcomed a son.
“From now on, the best part of me will always be my wife and my son. Welcome Billy Stamos (named after my father),” Stamos, 54, captioned a photo of the newborn nestled on his chest. “#NotJustanUncleAnymore #Overjoyed”
In an emotional December Instagram post, Stamos remembered his late father as he wrote about becoming a dad.
“I will certainly fall short of the father my pop was, but – I’m going to give it my all! #Balance #BillStamos#Hero,” Stamos captioned a throwback picture of the two.
“It kills me that my parents aren’t here to be part of this, but I know it probably wouldn’t be happening if they weren’t up there,” he previously told PEOPLE.
“You know how you put your father on a pedestal, and he’s a superhero, and then as you grow older, you go, ‘Ah, he’s just a man’? I never got to that point. Till the day he died, he was bigger than life to me.”
Stamos and 31-year-old McHugh, who wed Feb. 3 after two and a half years together, announced the pregnancy in December.
“I always wanted to be a dad. Clearly I had to do some work on myself first,” the actor said. “I have a youthful thing. People say, ‘Oh, you look young.’ You 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.’ … People would say, ‘You should have a child.’ I was like, ‘That ship has sailed.’”
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But Stamos said he felt prepared for parenthood.
“I’ll be a fun dad. I’ve been practicing for a long time,” he stated jokingly. “I’ve done every schtick you can do with a baby on TV … all the bits and jokes and diaper gags. I’ll probably just do all that stuff.”