Jessica Chastain looked gorgeous when she wore a custom Armani gown and Harry Winston jewels on the red carpet at today's Oscars in LA. She is nominated for best actress for her role in Zero Dark Thirty, pitting her against Jennifer Lawrence, Emmanuelle Riva, Quvenzhané Wallis, and Naomi Watts. She'll be pulling double-duty tonight, as she is also slated to present an award during the show. This isn't Jessica's first time attending the Oscars as a nominee — she was nominated for best supporting actress for her role in The Help when she attended last year. She ultimately lost out to her costar Octavia Spencer, but that nomination helped put her on the map as a star to watch at these events. Be sure to sound off on Jessica's red-carpet look in our Oscars beauty and fashion polls.