This evening's event is being chaired by Amal Clooney, Rihanna, and Donatella Versace, and debuts the Metropolitan Museum of Art's new exhibit Heavenly Bodies: Fashion & The Catholic Imagination.
Beatrice's appearance is the latest in a long tradition of royals attending the Costume Institute fundraiser.
Beatrice's late aunt Princess Diana attended in 1996 and wore Versace. In recent years, royal attendees have included Princess Maria-Olympia of Greece, Charlotte Casiraghi, and Queen Rania of Jordan. This is Princess Beatrice's first time at the iconic event.
While Beatrice lives in New York City, we'll see her in just a few weeks in Windsor for her cousin Prince Harry's wedding.
We hope she wears a fascinator as iconic as the one she sported at Prince William and Kate Middleton's wedding back in 2011.