Kate Beckinsale floated down the red carpet in a voluminous tulle gown by Marchesa.
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Ashley Olsen looked all grown up as she posed in a dramatic white gown from her twin sister Mary-Kate's label with her boyfriend, Justin Bartha. We're loving her sleek bob!
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Justin Timberlake sported a classic tux from his own William Rast line, while Jessica Biel, opted for a billowing Atelier Versace gown and sexy stilettos.
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Jessica Alba sparkled in a bright blue, black, and green mini by Jason Wu.
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Kate Hudson, Liv Tyler, and Kate Bosworth lit up the red carpet in gowns designed by Stella McCartney.
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Eva Mendes shimmered in a simple yet chic Calvin Klein creation.
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Blake Lively in Versace's Spring/Summer collection.
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Can't wait to see what the fashionistas strut down the carpet in tonight.