Gwyneth Paltrow, Renee Zellweger and Scarlett Johansson Dazzle at 2012 Met Gala

Monday's Costume Institute Gala was a who's who of Hollywood stars.

Held at The Metropolitan Museum of Art, the event celebrated the opening of Schiaparelli and Prada: Impossible Conversations. Stars like Gwyneth Paltrow, 39, Renee Zellweger, 43, and Scarlett Johansson, 27, came dressed to the nines, as did Rihanna, 24, and Jessica Alba, 31.

PHOTOS: Vote for which Met Gala look suits these stars best

While Paltrow wore head-to-toe Prada, "Where Have You Been" singer Rihanna turned heads in a backless, body-hugging Tom Ford dress and Christian Louboutin heels. The Avengers' Johansson looked like a modern-day princess in a Dolce & Gabbana dress and Christian Louboutin heels. She accessorized with a Judith Leiber clutch and Fred Leighton earrings.

MET Gala vid
Gwyneth Paltrow, Renee Zellweger and Scarlett Johansson Larry Busacca/Getty Images; iPhotoLive.com; Dimitrios Kambouris/Getty Images

Zellweger wore a custom Emilio Pucci silk gown with chiffon details and an organza train, while Alba donned a Michael Kors gown with Roger Vivier's "Pilgrim Coeur" clutch. Other attendees included Emma Roberts (in Escada), Cameron Diaz (in Stella McCartney), Sarah Jessica Parker (in Valentino), Kristen Stewart (in Balenciaga by Nicolas Ghesquiere) and Amy Adams (in Giambattista Valli).

The event also brought out several A-list couples, including Jessica Biel and Justin Timberlake (in Prada and Tom Ford, respectively) Emily Blunt (in Calvin Klein Collection) and John Krasinski, and Gisele Bundchen and Tom Brady (in Givenchy and Tom Ford, respectively).

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