Scarlett Johansson has given birth to her first child, a baby daughter called Rose, with her fiancé Romain Dauriac.
A spokesperson for the 29-year-old Avengers actress said both mum and daughter were doing well after the birth.
Marcel Pariseau added that the couple were seeking privacy and were supporters of the No Kids Policy, the celebrity movement to keep the children of famous people out of the public eye.
Scarlett Johansson and Romain Dauriac in February 2014, and below, her Art Deco engagement ring
Scarlett's Art Deco engagement ring
Johansson began dating Dauriac, a 31-year-old French journalist, in November 2012, a year and a half after the star divorced her husband of three years, Ryan Reynolds.
The pair got engaged last year. Showing off her vintage Art Deco diamond engagement ring at the Venice Film Festival in September, Johansson said she was "very happy".
"He’s my buddy," she told People, of her Paris-based partner. "Being engaged is an exciting time to enjoy and to really savour."
Scarlett Johansson in Lucy, her latest sci-fi thriller written and directed by Luc Besson
Johansson became pregnant in January. Around the same time she appeared on Good Morning America and said she was in no rush to get married, proclaiming: "I'm not doing any wedding planning."
Since then, she has very much avoided the spotlight and has not been photographed on the red carpet since March - despite promoting her latest sci-fi blockbuster Lucy, written and directed by Luc Besson.
Johansson was in France with Dauriac for much of last year as she worked on thriller.
Scarlett arriving for an appearance on New York's the Late Show with David Letterman in January this year
The actress has made no secret of her desire to have children in the past.
"I would like to have my own family, that would be nice," she told the Daily Mail late last year. "They say it's never the right time and I am sure that's true, but I think you have to plan it like anything else.
"At some point it is something I look forward to," she added. "I am fortunate in that I have had a long career - 20 years - that has been very diverse. So, you know, picking a time to plan a family feels like something that I could do and not feel as though I was missing out."
Johansson dated ad executive Nate Naylor for a year before confirmed her relationship with Dauriac. She has been linked in the past to Jack Antonoff, Josh Hartnett, Sean Penn and Benicio Del Toro.
She is one of the most sought-after talents in Hollywood, with a long list of credits to her name and a net worth of $55 million (£34 million).
Photos: Rex Features