The Girls alum made a sartorial splash on the red carpet in vibrant feathers and gold.
The star channeled bohemian glamour in a flowy rustic orange dress by Oscar de la Renta with a plunging neckline, paired with gold Tabitha Simmons open-toed heels.
One of the movie's leading men kept his look simple and streamlined in a navy ensemble.
The British actor donned a black three-piece suit for the event, finished off with a pair of sneakers.
The star behind one of the film's leads, Rick Dalton, opted for a three-piece suit, printed tie and shades.
The movie's director and writer posed alongside his wife while sporting all black at the premiere.