Billie Eilish's 2021 Met Gala look was inspired by her favorite Barbie doll

Billie Eilish attended the 2021 Met Gala on Monday night in New York City.

The co-chair this year wore a custom peach-colored Oscar de la Renta ball gown with corseted waist and long, flowing train.

The singer, 19, told Vogue on the steps of The Metropolitan Museum of Art that it was "time" to embrace her curves. 

MET GALA 2021: A LOOK AT THE STARS' RED CARPET OUTFITS

"It was time for this, and I feel like I've grown so much in the last few years," she told Keke Palmer. "I've always wanted to do this. I was just scared and didn't feel comfortable in my skin and I feel like I finally did."

Eilish then admitted her old Hollywood glamour look was inspired by Barbie. "I would ask for them for Christmas every single year. The dresses, genuinely that was my inspiration," she said.

Oscar de la Renta brand creative director told the New York Times Eilish "was very interested in surprising everybody with a look she hasn’t done before." He described the look as "very clean and sensual."

MET GALA 2021: HOW TO WATCH AND EVERYTHING ELSE YOU NEED TO KNOW

"It felt like a risk for her — it felt like something that made her nervous in a good way," he said. "At the end of the day, she’s a girl, and she wants to look pretty."

The label's other creative director, Laura Kim, told the outlet, "She was super excited to wear a beautiful gown."

Eilish complemented her look with dark black-wing eye linger and a layered platinum blonde bob hair cut. 

THE 2021 MET GALA WILL REQUIRE ATTENDEES TO BE VACCINATED, MASKED INDOORS

Along with the Grammy-winner, the Met Gala co-chairs include Timothée Chalamet, Amanda Gorman, and Naomi Osaka.