Jimmy Kimmel's 'healthy, happy' son Billy turns 6 months old

/ Source: TODAY

As babies go, Jimmy Kimmel's son Billy is pretty darn smiley.

And this week, he has something extra to smile about: After undergoing open-heart surgery shortly after his birth, Billy is thriving — and halfway to his first birthday!

"Billy is 6 months old today," Kimmel, 49, wrote on Twitter on Saturday. "He's healthy, happy & we're very grateful for your prayers, wishes & support of @ChildrensLA & other hospitals."

Billy will need to undergo two more open-heart surgeries when he's older. “We would like to get them over with and not have to think about it all the time, but it could definitely be worse,” Kimmel told The Hollywood Reporter in August.

The late-night host felt confident enough in Billy's recovery to crack some jokes. "“He’s doing great .... He's juggling. He's translating Flaubert from French into English. He's really an amazing kid,” Kimmel said, adding, “No — he smiles. That's pretty much it. He is very interested in ceiling fans."

The smiling is key!

Less than two weeks after Billy was born, Kimmel delivered an emotional monologue on his show about his son's surgery. He says it wasn't his intention to make headlines, but he understood the moment would draw widespread attention.

"I figured it would be a video that people shared. I know how it goes, when somebody cries on television .... I had no idea it would become a matter of national debate," he told Matt Lauer in a recent interview.

How will Billy react when he's old enough to watch the video himself?

"I just know he's not really going to care, and also knowing he's my son there's a good chance he'll make fun of me for it. And I have to say that will make me feel better than anything," Kimmel said.

Since that monologue aired in early May, both Kimmel and wife Molly McNearney have posted updates on Billy on social media and advocated for children's health coverage.

We're happy to see baby Billy doing so well!