The annual event, dubbed the style Oscars, is overseen by Vogue editor-in-chief Anna Wintour, who selects the celebrity committee who will serve as very special guests.
And her class of 2019 will feature two pop superstars, one of which might have an Oscar by the Met Gala for her role in "A Star Is Born", and a tennis ace.
The May 6 gala also has a theme - "Camp: Notes on Fashion", based on Susan Sontag's 1964 essay, "Notes on Camp".
GaGa and Serena have attended the invite-only Met Gala multiple times, but next year's event will be Harry's first.
Rihanna was the style star at this year's Met Gala, which was themed "Heavenly Bodies: Fashion and the Catholic Imagination", arriving on the red carpet in papal robes.