The newly-engaged stars will join Ryan Reynolds and Blake Lively, Bradley Cooper, Chadwick Boseman, Lupita Nyong'o, Lena Waithe, and Nick Jonas and Priyanka Chopra among the very special guests, alongside Katy Perry, Jared Leto, and Kerry Washington and her husband, athlete-turned-actor Nnamdi Asomugha.
Fashion gurus Tom Ford, Donatella Versace, Miuccia Prada, Valentino's Pierpaolo Piccioli, and Givenchy's Clare Waight Keller also feature on the list, which was hand-picked by Vogue U.S. Editor-in-Chief Anna Wintour, according to The Hollywood Reporter.
They will all grace the red carpet at the Metropolitan Museum of Art's annual fundraiser in New York, which will take place on May 6.
Wintour will co-chair the 2019 gala with Lady GaGa, Harry Styles, and Serena Williams, with this year's theme revolving around the new exhibit, "Camp: Notes on Fashion", based on Susan Sontag's 1964 essay, "Notes on Camp".
Cher, who has one stage costume from her 2008 Las Vegas residency featured in the exhibition, is expected to attend as a guest.
The 200-piece display will also include Bjork's infamous swan dress from the 2001 Academy Awards, and a fur cape and eye-catching custom suit designed for Liberace for his 1980s Sin City residency.
Rihanna was the style star at last year's Met Gala, which was themed "Heavenly Bodies: Fashion and the Catholic Imagination", arriving on the red carpet in papal robes.