Reese Witherspoon wore a simple black-and-white strapless column dress, but it couldn't be classier or more chic and unusual for America's Sweetheart. The look is Tom Ford -- Reese and other A-listers attended, and WALKED in the famous designers pre-Oscar runway show.

Meanwhile, Sienna Miller wore Oscar de la Renta -- which is actually black and navy. The American Sniper star's dress was see-through lace on the bottom half of the skirt and the bodice featured velvet bows.