Naomi Watts has named her new baby boy Samuel Kai Schreiber.
The actress and Liev Schreiber are celebrating the birth of Samuel, who weighed 7lbs 13oz.
"Both mum and baby are doing great," Naomi's publicist said.
The Australian actress, 40, and her 41-year-old actor-boyfriend are also parents to Alexander Pete Schreiber, born last year.
They have been dating for three years and co-starred in the 2006 drama The Painted Veil.
US actor Liev can next be seen in Defiance, also starring James Bond star Daniel Craig, next month.
Naomi's credits include Eastern Promises and King Kong.