The Art of the Party: How Stars Celebrated This Week's Best Fêtes

at the Whitney's annual Art Party in New York City. 

at the 2016 Guggenheim International Gala in N.Y.C. Hathaway in Dior.

at the 2016 Guggenheim International Gala. 

at the 2016 Guggenheim International Gala. 

at the 2016 Guggeinheim International Gala. 

in Dior at the 2016 Guggenheim International Gala Pre-Party in New York. 

at the 2016 Guggenheim International Gala Pre-Party. 

at the Museum of Modern Art's Film Benefit in N.Y.C. 

in Kitx at the Museum of Modern Art's Film Benefit. 

in Chanel at the Museum of Modern Art's Film Benefit. 

at the Capitol Records 75th anniversary celebration in Hollywood. 

at the Rolex Awards for Enterprise 40th anniversary gala in Los Angeles.

at L'Oreal Paris' Women of Worth Celebration. Kloss in Michael Kors. 

in Valentino, Roland Mouret, and J. Mendel at the Baby2Baby gala in Los Angeles. 

at the Baby2Baby gala. 

in Zuhair Murad at the Baby2Baby gala.

at an L.A. screening of Nocturnal Animals. 

in Tom Ford at an L.A. screening of Nocturnal Animals.

at Burberry's Tale of Thomas Burberry celebration in SoHo.

at the opening of The Webster South Coast Plaza, Costa Mesa.

at the opening of The Webster South Coast Plaza, Costa Mesa.

at the opening of The Webster South Coast Plaza, Costa Mesa.

at the opening of The Webster South Coast Plaza, Costa Mesa.

at Variety and WWD's second annual StyleMakers Awards in West Hollywood.

in Christopher Kane at the Governors Awards in Hollywood. 

at Minkoff's Los Angeles flagship to celebrate the brand's holiday collection with Smashbox cosmetics.