Millie Alcock wears Balenciaga at the New York premiere of Supergirl

Millie Alcock channeled her dark punk side in a Balenciaga look at the red carpet premiere of Supergirl on Monday night in New York City.

The House of the Dragon alum wore selections from the Spanish luxury fashion house’s Spring 2026 ready-to-wear collection, designed by creative director Pierpaolo Piccioli. Cast in monochrome black, the look consisted of a strapless structured bodice with a bubble peplum motif below the waist, black pants, and leather coordinating gloves.

Alcock continued her work with Balenciaga, also wearing the label’s Duchess pumps. As for jewelry, the actress wore cascading diamond earrings by Jacob & Co. that added sparkle to Alcock’s overall look.

Alcock’s golden blonde hair was styled with a middle part and soft waves by stylist DJ Quintero. The actress’ makeup highlights continued her punk edge with bold eyebrows, dark eyes, and a neutral, glossy lip by artist Tyrone Mahahausen. Alcock’s Supergirl premiere outfit was supervised by stylist Felicity Kaye.

The actress’ Balenciaga look made its runway debut as part of Paris Fashion Week in October 2025. The Spring 2026 ready-to-wear collection marks the debut of designer Pierpaolo Piccioli as the brand’s new creative director, who was appointed in May 2025 and took over in July of the same year.

“There were many tributes to the founder, including a T-shirt, white shirt, black leather cape version of the founder’s famous Darth Vader-inspired 1967 wedding ensemble, and, most strikingly, a number of balloon dresses and skirts in black leather,” Miles Socha wrote in WWD’s review of the collection.

“I don’t want to deny what has been here before,” Piccioli said after the show, acknowledging that his collection combined Balenciaga’s traditional design codes with his own vision for the brand.

Supergirl follows Kara Zor-El, played by Alcock, as she teams up with unlikely allies to seek justice when the people she loves most are threatened by an adversary. The film will be released in theaters on Friday.