Gaga, who is all set for her maiden performance at the Oscars, looked stunning in couturier Azzedine Alaia's plunging white gown that totally stole the spotlight. In Pics: Hollywood celebs dazzle at Oscars 2015 red carpet!
This will be her first performance post her engagement to longtime boyfriend Taylor Kinney, who could not come to cheer for her fiancee due to some "work".
Hollywood fashionista and Oscar-winning actress Nyong'o looked like a mermaid tangled in a pearl gown designed for her by Calvin Klein Collection's Francisco Costa.
The figure-hugging dress featured intricate white beading from top to bottom, a halter neckline and sexy keyhole cut-out. This was the '12 Years A Slave' actress' second outing at the Oscars.
Best supporting actress nominee Arquette opted for a one-shoulder black-and-white gown by Rosetta Getty which she paired with a Ferrgamo clutch and shoes.
French beauty Cotillard, nominated for Best Actress for her role in "Two Days, One Night", stunned in a white Dior gown with black details. She will also be a presenter at the star-studded event, which is hosted by Neil Patrick Harris.
Another best actress nominee, 'Wild' star Reese Witherspoon wore an off-shoulder black-and-white gown by Tom Ford at the Oscars red carpet. She looked elegant with her lustrous golden locks untied.
British actress Felicity Jones, a best actress nominee for her role of a compassionate wife in "The Theory of Everything", donned an Alexander McQueen silver gown. She kept her hair and make-up sleek and simple, a perfect complement to her voluminous dress.
Gaga, who is all set for her maiden performance at the Oscars, looked stunning in couturier Azzedine Alaia's plunging white gown that totally stole the spotlight.
In Pics: Hollywood celebs dazzle at Oscars 2015 red carpet!