Steve Martin has played a devoted father to more than 20 children on the big screen, but in real life, the 67-year-old actor just welcomed his first child with 41-year-old wife Anne Springfield.

The couple, who have been married for nearly six years, are extremely private, according to the Daily Mail, and succeeded in keeping the December birth a secret until now.

"They've had a baby, and how they kept it a secret nobody knows," a source told the New York Post. "Steve's very private."

"They are thrilled," the source added. "They worked hard to have the baby."

The birth was exposed when the “It’s Complicated” star and his wife were sighted with the newborn in Los Angeles, not far from their home. A rep for the couple confirmed the news to USA Today, but neither Martin nor Springfield has yet commented.

Springfield and Martin married in 2007 in a private ceremony at Martin’s home that was apparently kept so tightly under wraps that none of the guests, who included Tom Hanks and Diane Keaton, knew it was a wedding until they arrived.

Although the child, whose name has not yet been announced, is Martin’s first, he has decades of experience playing doting fathers in comedies like “Parenthood,” “Father of the Bride,” and “Cheaper By The Dozen.”

“I played fathers so many times, it’s like being one,” Martin said in an interview with IGN in 2003. “I’ve had children of every age. And like I say, I get to do everything but the dirty work. Their parents have to take them home and deal with all that.”

He added that the experience of working with child actors can vary a lot, often depending on their parents, but Martin did share one anecdote that seemed to especially impress him.

“I did a movie, 'A Simple Twist of Fate.' I was working with two twins. They were about three. This is in Atlanta. And they were delightful. And they were funny and they were sweet. And I asked the parents, I said, 'Why are your children so fabulous?' And she kind of looked surprised and said, 'Well, we raised them with humor.' And I thought gee, what a great answer. Get kids into the humor mode."

But despite his success at onscreen parenting, Martin has said that his relationship with his own father was rocky.

“My father’s attitude toward my show-business accomplishments was critical. After my first appearance on ‘Saturday Night Live’ . . . he wrote a bad review of me in the newsletter of the Newport Board of Realtors where he was president,” Martin wrote of his father, Glenn Vernon Martin. However, in a Reader’s Digest column over 10 years after his father’s death, Martin talked about his struggle to reconcile their strained relationship as his father declined, writing, “In his death, my father . . . did something he could not do in life. He brought our family together.”