"The X-Files" star and her boyfriend Mark Griffiths welcomed a baby boy, Felix, into their home on Wednesday, Oct. 15, reports People.
Felix Griffiths weighed 6 lbs., 15 oz. and was born in London.
Anderson, 40, has another son with Griffiths, 1-year-old Oscar.
She also has a 13-year-old daughter, Piper Maru, from her first marriage to "X-Files" series assistant art director Clyde Kotz, whom she later divorced. Following that was a brief, 16-month marriage to documentary filmmaker Julian Ozanne. She then started dating Griffiths, a businessman.