The Met Gala is fashion's biggest night, but what is it? And why are celebs wearing elaborate (and sometimes just weird) dresses? Us Weekly has you covered with answers to all of your burning questions about the Met Gala. What Is the Met Gala? The Met Gala is a fundraiser for The Metropolitan Museum of Art's Costume Institute. Also known as The Costume Institute Benefit, the event is the Costume Institute's "primary source of funding for exhibitions, publications, acquisitions, operations and capital improvements," per The Met.