The superstar stepped out for the annual event on Monday in an Oscar de la Renta metallic bodysuit with fringe-detailing and a plunging neckline.
Dion's hand-beaded look took over 3,000 hours to make with 52 master embroiderers working on it — and weighs over 22 pounds, according to the designer's official Twitter account. Dion, 51, paired her look with an extravagant headpiece.
For this year's Met Gala, the theme is "Camp: Notes on Fashion," which was inspired by a seminal 1964 essay by Susan Sontag in which she describes the phenomenon as something that shan't be talked about: "To talk about Camp is therefore to betray it."
The theme is the basis for the Costume Institute's spring exhibition.
Speaking to E! News on the carpet, Dion admitted that she initially didn't understand Monday's theme. "At first I was a little bit confused when I heard 'Camp,'" she told the outlet.
"I thought it meant 'camping.' We're going camping! We're going to be at the Met and everyone is going to stay and sleep all night together. But, no."
The Associated Press contributed to this report.