Insiders also revealed the pair have set about planning their divorce but have an amicable relationship, with both the 40-year-old actress and the 38-year-old star said to be "incredibly sad" about their break up.
In similar statements posted on their social media accounts on Sunday, the pair admitted they were "really disappointed" about the breakdown of their marriage, and insisted they "tried hard" to make it work.
Pratt wrote on Facebook: "Anna and I are sad to announce we are legally separating. We tried hard for a long time, and we're really disappointed. Our son has two parents who love him very much and for his sake we want to keep this situation as private as possible moving forward. We still have love for each other, will always cherish our time together and continue to have the deepest respect for one another."
It came after Pratt praised Faris in April at his Hollywood Walk of Fame star ceremony.
He said: "I want to thank my wife Anna, I love you. You've given me so much. You gave me the greatest star in the galaxy in my little boy, I love him and I love you.
"We have bonded to make this molecule that is more important to me than air or water, and without it none of this means anything to me. With every challenge, with every day, week, month, decade, we become more bonded."
-Bang! Showbiz
