Oscar Night's 15 Best Dressed

She doesn’t need any Help when it comes to fashion: channels Old Hollywood glamour with aplomb in a red Giambattista Valli Haute Couture halter with a tie neck, plus a sparkling silver clutch by Louis Vuitton, Louis Vuitton High Jewelry and Brian Atwood heels.

Supporting her Best Actor nominee , commands attention in a structured velvet Atelier Versace gown with a high slit, worn with simple Salvatore Ferragamo peep-toes and $2.5 million worth of Neil Lane jewels.

The is already a winner in her vintage-feeling peplum Louis Vuitton frock, accessorized with a light pink Bottega Veneta clutch, 30-carat Fred Leighton for Forevermark choker and 19th century Fred Leighton bow brooch at her waist.

Also wearing one of the night’s hottest colors, last year’s picks a classic Dior Haute Couture gown with a twist (by way of subtle polka dots) and megawatt gems by Harry Winston.

Best Supporting Actress nominee Jessica goes for all-out glamour in her hand-embroidered Alexander McQueen bustier gown, worn with $2 million worth of Harry Winston yellow diamonds and Brian Atwood heels.

The did it up in her signature supersexy style, choosing a plunging Art Deco-style Zuhair Murad gown, a mirrored Salvatore Ferragamo clutch and Jimmy Choo sandals.

Complementing her striking natural hairstyle with an embellished emerald Vera Wang gown, a Judith Leiber clutch, dazzling Lorraine Schwartz diamond-and-emerald jewels and Jimmy Choo sandals, The Help’s Best Actress nominee makes a dramatic entrance.

Continuing to make a sparkling statement on the red carpet, the Bridesmaids beauty wows in a fully sequined one-shoulder Vivienne Westwood gown, Chanel Fine Jewelry and Jimmy Choo platforms.

Keeping her promise to stay loyal to certain designers, The Help’s Best Supporting Actress winner is elegant in a draped pale-gold beaded Tadashi Shoji boatneck gown, which she pairs with Jimmy Choo shoes, a Judith Leiber clutch and Neil Lane jewels, including 50-carat diamond earrings.

Guess she saw something she liked at New York Fashion Week’s Marchesa show: date wears a straight-off-the-runway, liquid-gold lamé Marchesa gown with a Judith Leiber clutch, Rene Caovilla heels and Lorraine Schwartz jewelry.

, who presented an award, looks seriously stylish thanks to a navy Carolina Herrera gown, striking sapphire-and-emerald Bulgari jewels, a Roger Vivier clutch, Stuart Weitzman heels and a sleek high bun.

The seems to have color-coordinated with copresenter , also wearing a shimmering metallic gown (Diaz’s is Gucci) with nearly $1 million worth of Tiffany & Co. jewels, plus Salvatore Ferragamo pumps.

The Descendants actress mixes modern – via her sleek Monique Lhuillier racerback gown, Stuart Weitzman heels and Judith Leiber clutch – with retro glamour (see her delicate Mimi So for Forevermark jewelry and romantic waves).

Nominated for the Bridesmaids screenplay, Kristen keeps things breezy in a tiered tan J. Mendel gown and beachy hair, plus a Judith Leiber clutch and Neil Lane gems.

“It’s one of my favorite dresses I’ve ever worn,” the gushes of her custom lavender Giorgio Armani gown, the perfect palette for a whopping 114 carats of Chopard diamonds.