Sienna Miller gave birth to a baby girl over the weekend, according to US media reports.

The 30-year-old actress and her fiancé Tom Sturridge (26) welcomed their first child into the world over the weekend in London, and while the couple have not released official details about the baby, E! Online revealed that the baby girl is named Marlow.

Although news of her pregnancy broke earlier this year, the usually private Miller was reluctant to talk about it in an attempt to keep her personal life out of the public eye.

In March, she told British Vogue: "I'm in my second trimester, so I'm I-can-talk-about-it pregnant, 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."

Miller started dating The Boat That Rocked actor Sturridge - who is close friends with Twilight Saga star Robert Pattinson - just a few months after she split from then-fiancé Jude Law for a second time in February 2011.