By Breaking Celebrity News Staff

Reese Witherspoon was the pregnant belle of the ball at the Cannes Film Festival Saturday.

For the premiere of her new film, Mud, Reese stole the show from the film's star Matthew McConaughey -- Witherspoon has a small supporting role -- in a stunning low cut indigo gown, accented by some major diamond bling.

Earlier in the day, for the press photo call, she wore a form-fitting black Versace dress with fuchsia stilettos.