The mother-to-be flaunted her baby bump wearing a black Versace dress at CinemaCon in Las Vegas on Monday where she was promoting her new movie "Teenage Mutant Ninja Turtles: Out of the Shadows," along with costar Will Arnett, reported People magazine.
Fox, 29, is already a parent to sons Noah Green and Bodhi Green, with estranged husband Brian Austin Green.
The couple, who filed for divorce in August after five years of marriage, have been spotted together several times in the recent months.