Sienna Miller, 30, gave birth to her first child with fiance Tom Sturridge, 26, over the weekend in London, Us Weekly reports.
Details on the baby's gender, name and weight have not yet been reported.
Miller briefly discussed her pregnancy with Vogue U.K. in the magazine's March issue. "I'm in my second trimester, so I'm I-can-talk-about-it pregnant," she said. "Even though I'm under strict instructions not to say anything as it would completely defeat the point of everything I've tried to achieve in the last eight years."
More stars who are expecting babies in 2012:
The reality star is pregnant with her second child, a baby girl.
The "Bachelor" star is expecting her second child with husband Tye Strickland.
Wilde is expecting her first baby with fiance Jason Sudeikis.
Barrymore is expecting her second child with husband Will Kopelman.
Clarkson announced her pregnancy on Twitter Nov. 19, 2013. She's expecting her first child with husband Brandon Blackstock.
Goodwin and her fiance and "Once Upon A Time" co-star Josh Dallas are expecting their first child together.
Jenni "JWoww" Farley
JWoww, who's expecting her first child with fiance Roger Mathews in July, is set to welcome a little baby girl.
Kenan Thompson And Wife
The "SNL" star and his wife Christina Evangelina are set to welcome their first child.
Lil Kim debuted her baby bump during NYFW on Feb. 12.
Aguilera is reportedly expecting her second child, her first with fiance Matthew Rutler.
The former "Office" star is expecting her second child.
The actress is reportedly expecting her first baby with fiance, Romain Dauriac.
Kunis is reportedly expecting her first child with fiance Ashton Kutcher.
Keibler is expecting her first child with new husband Jared Pobre.
Carson Daly and longtime love Siri Pinter are expecting their third child.
Snooki is expecting her second baby with fiance Jionni LaValle.