The actress, 39, gave birth on Tuesday, April 22 with her husband by her side according to a statement from her spokesperson obtained by People magazine.
"Happy to announce that today we are the proud parents of our second daughter, Frankie Barrymore Kopelman," the couple told People.
During her pregnancy, Barrymore stayed true to her heart-themed style through much of the awards season, she insisted pregnancy wasn't the time to strive for perfection.
"You're not supposed to look perfect while you're making babies. Making babies is the perfection," she told Women's Health.
Instead, Barrymore took the time to enjoy her experience and indulge in her cravings - even if that meant a little extra weight gain.
"I don't ever pose, 'I'm just so fabulous and I lose it like that.' I want to enjoy the pasta right now! What's 10 lbs.?" she told Ellen DeGeneres in January.
The Grey Gardens star told People in February, "I'm relieved I'm having another girl. I have everything I need. It's all about hand-me-downs and room sharing and all that stuff. I'm pretty psyched about that!"
According to Yahoo, Olive is also excited to be a big sister. Barrymore said, "She just really loves babies and kids. I have her in a lot of classes ... I like when she's so open-hearted to people and her surroundings."
The actress also spoke to the Associated Press earlier this month about how becoming a parent is "the greatest thing I've ever done in my life," although it has brought on new anxieties.
"I try to have a sense of humor about how... [much] you need to learn and tackle," she said, "and how to remain fun-loving and not, like, uptight because there's so much to care about and to learn about."
"It used to be work first and now it's life first," she noted. "So even though I'm doing a lot, there's a lot of things that have slowed down. I don't make that many movies anymore. I'm not really producing right now. And I'm trying to do jobs where I can work from home or be at home by dinnertime if I do have to go out to meetings. You just sort of change your life."
