Little Frederick was born on 23rd July in the couple's home town of Austin, Texas. Chris was eager to share the news with his fans, posting a sweet photo of his son with the message, 'So incredibly blessed and forever grateful for my amazing wife & our healthy baby boy. Laina delivered me a miracle.'
So incredibly blessed and forever grateful for my amazing wife and our healthy baby boy. Laina delivered me a miracâ€¦ https://t.co/NR5harArB3— Chris Klein (@iamchrisklein) July 27, 2016
Wife Laina also shared the happy news online, writing, 'This little champ has already mastered his warrior pose and is doing great, our hearts are bursting with love and joy.'
The 37-year-old American Pie star announced the lovely baby news on Twitter on the day of his birthday, with a photo of his wife's beautiful baby bump, surrounded by flowers.
In the caption, he wrote: 'My beautiful wife Laina and I are expecting our first child. 23 weeks along. Gratefully blessed on my 37th B-Day.'
My beautiful wife Laina and I are expecting our first child. 23 weeks along. Gratefully blessed on my 37th B-Day. pic.twitter.com/BFNbKhSemY— Chris Klein (@iamchrisklein) March 14, 2016
The daddy-to-be made the announcement via Twitter
Chris' wife Laina also shared the news with her followers on Instagram at the time, using the same photo and writing: 'Happy Birthday to my loving husband who always knows how to put a smile on my face. Thank you for making me your wife and a soon to be a Mother. You make every day feel like a miracle. I love you.'
The pair tied the knot in August last year, at a ceremony in Montana. Chris popped the question during the Christmas holidays in December 2014, after three years of dating.
Before his relationship with Laina, Chris was engaged to Katie Holmes, but they split up in 2005. The two movie stars started dating in 2000 and got engaged three years later.
Katie got engaged to Tom Cruise just three months later, but Chris said she was always respectful to him and called him to share the news before he heard it from someone else.
'When we were breaking up, we kept it to ourselves for a while. It looked like it was Katie and Chris together and two seconds later Katie and Tom together, but that's ridiculously compressed... Kate was incredibly respectful about the decision she was making to move on', Chris said.
'She called and said, "Listen I want you to know before you see it anywhere else".'
Chris played Chris 'Oz' Ostreicher in American Pie, American Pie 2 and American Reunion
The American Pie star also opened up about his alcohol addiction in 2010, after he checked into rehab: 'It got to the point where I was a fragile shadow of the young man that came into this business. Today, I'm the luckiest guy alive.'
The dad-to-be became famous for his role as Chris 'Oz' Ostreicher in the American Pie films, but he's also starred in The Big Bang Theory and in the film Authors Anonymous.
Congratulations to the happy couple!