Congratulations to Amanda Seyfried!
The Mean Girls star gave birth to her first child, a baby girl, with husband Thomas Sadoski, Sadoski's rep confirms to ET.
WATCH: Amanda Seyfried's Fiance Thomas Sadoski on Her Pregnancy: 'She's Already an Incredible Mom'
ET last spoke with Seyfried at the premiere of her new film, The Last Word, earlier this month, where she joked she was "12 months pregnant."
"I'm ready," the 31-year-old actress confessed, while Sadoski -- who announced the two had secretly married just last week -- gushed about becoming a dad.
"I'm blown away by her every day," the 40-year-old actor said of Seyfried.
"She does look about ready to pop. It's a pretty amazing thing. I just get to sort of hang back and watch it all happen," Sadoski added. "That's the great joy for me, trying to learn as much as I can -- try to stay out of the way and not screw anything up too much."
WATCH: Pregnant Amanda Seyfried Poses in Crop Top on ‘Vogue Australia’ Cover, Says She’s ‘Ready’ to Be a Mom
Seyfried first announced her pregnancy in a big way, debuting her baby bump while promoting Givenchy's new fragrance in November. See more in the video below.