The former Nickeloden star welcomed his first child with wife Paige O'Brien, he announced on Instagram on Monday, alongside the first photo of the little one. The couple revealed they were expecting in August, just over a year after they tied the knot.
Peck simply captioned the close-up of his son's face with the bundle of joy's name: "Max Milo Peck." O'Brien, meanwhile, shared another shot of their baby boy to her Instagram, this time of him swaddled in a brown blanket, and sporting a white hat. The newborn stares up into the camera in the cute snap, which his mom also captioned with his name.
ET spoke with Peck in August, when he revealed that his good friend and former Grandfathered co-star, John Stamos, had taught him a thing or two about fatherhood.
"Stamos is already crushing fatherhood. No joke," Peck raved of the actor, who is dad to young son Billy. "Can you imagine John Stamos changing a diaper? I mean, that baby is lucky. But his son, Billy, is gorgeous and if I can get anything quite like that, I'll be overpaid."
"He's done this incredible, beautiful transition into being a dad," he continued. "And I know that he wanted to have a kid for so long. So to watch him sort of flourish in that way has been a joy."
See more -- including what Peck had to say about making Stamos his child's godfather -- in the video below.