The Avengers actress, 29, and her french journalist fiance Romain Dauriac have welcomed their first child together, a daughter named Rose, her rep confirmed to E! news.
Johansson and Dauriac have been engaged since September 2013 and several sources claimed they were set to tie the knot in August.
Though the actress has kept her public appearances to a minimum as of late, she and Duriac have been photographed several times strolling around New York City over the past few months.
Johansson will next star in Deep Down in 2014 and will reprise her role as Natasha Romanoff/Black Widow in Avengers: Age of Ultron in 2015. The star is also set to voice Kaa in the upcoming adaptation of The Jungle Book also in 2015.