The Academy of Motion Picture Arts and Sciences, which organises the ceremony, is sticking to the tradition that sees the previous year’s winners handing out the new year’s trophies.
Colman won Best Actress for The Favourite last year, while Malek took Best Actor for Bohemian Rhapsody.
King won in the Best Supporting Actress category last year for If Beale Street Could Talk and Ali was named Best Supporting Actor for Green Book.
“We love the tradition of having the previous year’s Oscar-winning actors on stage to celebrate the achievements of their peers and are thrilled to welcome back these four great talents,” producers Lynette Howell Taylor and Stephanie Allain said in a statement.
The 2020 Oscars will take place on 9 February.
You can view a full list of nominees here.