Lea Michele
Lookin' good, Lea! The star was radiant in a Fausto Puglisi frock and Christian Louboutin sandals.
Shay Mitchell
Is this the sexiest look of the night? You betcha! Shay nails it in this lacy two-piece Misha Collection design.
Lucy Hale
There are plenty of words that come to mind upon seeing this Christian Dior dress (red hot, for example) but right now we're just going to go with: Stunning! Plus, her studded Brian Atwood sandals killer.
Nina Dobrev
Saving the best for last! The actress finished off a very stylish week with this fun Vionnet ensemble paired with the perfect pink Kurt Geiger pumps.
Kendall Jenner, Kim Kardashian, Kylie Jenner
Sister act! Kim and Kendall, looking flawless in Balmain and Oriett Domenech respectively, joined birthday girl Kylie, wearing Sass & Bide, on the blue carpet.
Taylor Swift
Yup, confirmed once again: The singer is really into the whole crop top trend! This time it's a mint tweed Novis number.
Selena Gomez
Well suited! The star looked elegant in her Saint Laurent lady tux.
Demi Lovato
Usually she goes for edgy, but this time Demi tried out a more conservative style with this ivory Elisabetta Franch dress—and we're liking the results!
Jordin Sparks
Just when you think you've seen every print imaginable, the singer debuts this fun one on her Simply Intricate outfit.
Ariana Grande
The pop star kept it simple in a white George Chakra frock with nude pumps.
Hilary Duff
The singer paired her modest Sachin & Babi Noir crop top with a vintage leather pencil skirt.
Sarah Hyland
Holy smokes! The night's co-host dazzled in a plunging (and backless!) Marc Jacobs mini dress.
Ian Somerhalder
No suit, no problem! The actor still looked swoon-worthy in a tee and jeans.
Ansel Elgort
Winner of most contagious smile has got to be this guy!
Chloe Grace Moretz
Skin is in! The If I Stay star rocked a tiny Valentino tube top and short shorts.
Hailee Steinfeld
The Begin Again actress mixed fabrics and prints with her Elie Saab dress.
Zendaya
The Disney star rocked head-to-toe highlighter pink with a Material Girl halter dress and Christian Louboutin pumps.
Bella Thorne
The actress brightened up in a custom Candies Couture floral frock by Johnny Wujek.
Tyler Posey
The night's co-host looked quite sharp in a silver suit jacket.
Janel Parrish
The Pretty Little Liar actress went with a crop top and maxi skirt combo.