If the Oscars gave out an award for best dressed, it would be the most hotly contested prize of the night.

Hollywood's biggest stars are turning on the style as they walk the red carpet for the glittering ceremony in Los Angeles on Sunday.

They include Clueless star Alicia Silverstone (above), who looks a total Betty in Christian Siriano with long black opera gloves, after appearing in best picture nominee Bugonia.

Australian actress Rose Byrne (below), nominated for If I Had Legs I'd Kick You, wore a black custom Chanel dress embroidered with an intricate floral pattern.

Bella Thorne decided to go with a softer touch in black feathered cuffs and a sheer slip.