According to the Daily Mail, the star wants to work again with the director in the final entry of the controversial trilogy.
Kidman, who starred in the first film, Dogville, was unavailable to play in the second film, Manderlay.
In the movie Manderlay, the role of Grace was played by Bryce Dallas Howard, and there are talks of her returning and sharing the role of Grace with Kidman in the final film of the series.
The production for Washington is set to begin in the summer of 2007.