A spokeswoman for the actress said Friday that Fox and her husband, Brian Austin Green, are expecting their second child together. Publicist Dominique Appel offered no other details.
Fox and Green welcomed a son, Noah, in September. Green also has a son named Kassius from a previous relationship with actress Vanessa Marcil.
Fox and Green were married in 2010. They began dating in 2004.
Fox was last seen on screen in Judd Apatow's 2012 comedy, "This Is 40." She is currently filming "Teenage Mutant Ninja Turtles."