Lambert, 29, turned heads wearing a Roberto Cavalli gown that featured a thigh-high slit. "Wide Awake" nominee Perry, meanwhile, wowed wearing a mint green Gucci dress.
Despite her penchant for wearing provocative looks, Rihanna looked ladylike in a custom Azzedine Alaia dress, Neil Lane jewelry and Manolo Blahnik shoes. Her boyfriend Chris Brown, meanwhile, suited up in Lanvin.
Presenter Jennifer Lopez, 43, emulated Angelina Jolie's 2012 Academy Awards look when she donned a leg-baring Anthony Vaccarello dress. The Latin pop star completed her look with Tom Ford shoes, Norman Silverman jewels and a Jimmy Choo bag.
Other stars who walked the red carpet include Beyonce (Osman), Justin Timberlake (Tom Ford), Adele (Valentino), Frank Ocean (Dior Homme), Alicia Keys (Azzedine Alaia), Wiz Khalifa (Tom Ford) and Faith Hill (J. Mendel).