27 February 2012
Last updated at 08:04
Best actress nominee Michelle Williams wore a vibrant red Louis Vuitton peplum dress to this year's ceremony. The backless gown was offset by a pink Bottega Veneta clutch and Forevermark jewels.
Actress Angelina Jolie presented The Descendants' writers with best adapted screenplay. Her dress, by Atelier Versace, attracted a few wolf whistles as she took to the stage at the Kodak Theater.
French actor Jean Dujardin took home the best actor award for his role as George Valentine in The Artist. Before the ceremony, he practised some of the facial contortions that won him the prize.
Glenn Close wore a midnight green Zac Posen dress, which was recently seen on the catwalk at New York fashion week. The tail had floral detail, while the matching blazer featured satin lapels. The actress, pictured top right with make-up artist Matthew Mungle, was nominated in the best supporting actress category for Albert Nobbs.
Actress Natalie Portman attended the awards with her fiancé Benjamin Millepied. She handed out the best actor award to Jean Dujardin, dressed in a vintage red chiffon silk Christian Dior Couture gown with velvet polka dots.
Actress Sandra Bullock presented the award for best foreign language film, which she introduced in German. She walked the red carpet wearing Marchesa. "You find one [dress] and then you make your way through others, and you usually make your way back to your original choice," she said. "That's what happened."
Octavia Spencer (left) won a standing ovation as well as her Oscar for best supporting actress. She wore a beaded silk Tadashi Shoji gown. Her co-star in The Help, Viola Davis (centre), wore a bright green Vera Wang dress. Meanwhile The Girl With The Dragon Tattoo, Rooney Mara, became the girl in a cleavage-bearing Givenchy haute couture by Riccardo Tisci.
Gwyneth Paltrow won praise from fashion writers for her daring caped gown by Tom Ford. Penelope Cruz took to the red carpet three years after her best actress win in a custom, off-the-shoulder Armani Prive organza dress.
Sacha Baron Cohen arrived at the awards in character for his new movie, The Dictator, where he spilled contents from an urn onto the carpet. He was later escorted off the red carpet after tipping ash over TV host Ryan Seacrest.
Actress Emma Stone wore Giambattista Valli and Brian Atwood platform sandals. She presented the visual effects award with Ben Stiller.
Actress Meryl Streep wore a gold Lanvin dress to the awards and thanked her husband first when she picked up the best actress award for her role in The Iron Lady.
Actress Kristin Wiig, the star and co-writer of Bridesmaids, wore a nude tone J Mendel dress, which she contrasted with a dark manicure and Neil Lane jewellery.
Jennifer Lopez walked the red carpet in a figure-hugging art deco Zuhair Murad dress.
Actress Cameron Diaz wore a fishtail gown with an embellished skirt by Gucci, and topped the outfit off with platinum Tiffany jewellery.
Jessica Chastain, who was nominated for best supporting actress, wore a striking copper and black gown by Alexander McQueen, with $2m (£1.25m) worth of diamonds by Harry Winston.
Leading men: Despite all being nominated for the best actor award George Clooney, Gary Oldman and Brad Pitt all went home empty handed.