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: