The longtime couple, who never got married, were together since 2005 and have two sons together: nine-year-old Alexander and seven-year-old Samuel.
The two have decided to separate with mutual consent, according to The Hollywood Reporter.
They have issued an statement which reads, 'Over the past few months we've come to the conclusion that the best way forward for us as a family is to separate as a couple.
'It is with great love, respect, and friendship in our hearts that we look forward to raising our children together and exploring this new phase of our relationship.'
Schreiber, 48, and Watts, 47, have also asked their fans and media to respect their privacy at the moment.
'While we appreciate your curiosity and support, we ask the press to be mindful of our children and respect their right to privacy.'
Photograph: Alberto E Rodriguez/Getty Images
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