Connelly is an Oscar winner

The baby was born Tuesday, said publicist Cari Ross. No other details were released.

Oscar-winning star Connelly, 32, has a five-year-old son, Kai, from a previous relationship.

She won the best-supporting actress Oscar in 2002 for her role as the wife of maths genius John Forbes Nash, played by Russell Crowe, in A Beautiful Mind.

The actress met her husband on the set of the film. Bettany, also 32, played Nash's mysterious classmate.

Connelly has said that she and Bettany did not start seeing each other until about a year after filming ended.

They were married in December last year at a private ceremony in Scotland.

Connelly starred in this year's Hulk, directed by Ang Lee, while Bettany's forthcoming films include Master and Commander: The Far Side of the World, co-starring Crowe, and Wimbledon, co-starring Kirsten Dunst.