The announcement was made by the Broadcast Film Critics Association (BFCA) and the Broadcast Television Journalists Association (BTJA), which organises the awards ceremony.
"We are absolutely thrilled to have Olivia hosting this year's ceremony, and know that she will deliver an entertaining and sharp-witted evening to everyone in the room, and the viewers at home," BFCA President Joey Berlin said in a statement.
"Beyond her skills as an actress, Olivia's work as an activist within the industry gives her a powerful voice, making her the perfect candidate to lead this night honouring the best and brightest in film and television," he added.
Munn, who had recently alleged that director Brett Ratner sexually harassed her, has been vocal about changing the environment of sexual misconduct in Hollywood.