Rosamund Pike has given birth to her second son at home.
The 35-year-old Gone Girl star and her long-term partner Robie Uniacke, 54, welcomed their new arrival on December 2, according to People magazine.
No details about a name have been released.
The new baby is a little brother for the former Bond girl and Robie's two-and-half-year-old son, Solo.
Rosamund recently explained that she had an urge to have another baby after she finished work on Gone Girl, the film adaptation of Gillian Flynn's best-selling thriller.
The English actress played Amy Dunne, whose husband Nick (Ben Affleck) is suspected after she disappears on their anniversary.
She said: "After filming I just knew I had to go out there and make a human being.
"The film was so tough and such a hard experience that the instant I'd finished I thought: 'I need to bring something positive into the world. Life is good with little people around'."
In September, Rosamund compared her baby bump with TV presenter Charlotte Hawkins' while appearing on Good Morning Britain. Charlotte, 39, is expecting her first child in February.
Rosamund joked: "Having a baby is a great project to have after playing a character as un-maternal as Amy Dunne.
"After playing a character like that, it's good to be bringing a new life into the world!"
She has also spoken about how much she loves being a mum to a son, saying: "If you have a little boy, you walk through the door at home and you get on to the floor with some Lego – that's a wonderful antidote."