Sienna Miller has reportedly given birth.

The 30-year-old British actress and her fiance Tom Sturridge welcomed their first child into the world over the weekend, reports Us Weekly.

Sienna is believed to have given birth in London. Details about the baby's gender, name and weight are not yet known.

Sienna and Tom enjoyed a romantic babymoon to Italy earlier this year.

She was said to be "counting down the days" until the birth and was looking forward to the prospect of motherhood.

Although Sienna has stayed out of the public spotlight in recent months, she did reveal she was coping well with her first pregnancy.

"I'm feeling fine... It's all progressing nicely and it's very exciting," she told UK magazine Vogue.

Sienna and Tom started dating in mid-2011 following her split from actor Jude Law.

The blonde beauty showed off an impressive engagement ring in February.

"It's quite adorable the way they are together. This baby is going to be so loved," an insider gushed to British magazine Closer recently.