Golden Globe and Emmy winners Fey and Poehler previously hosted the Hollywood Foreign Press Assn. gala from 2013 to 2015, bringing their longtime rapport and banter to the Globes stage.
The news was announced by Poehler herself at the Television Critics Association winter press tour on Saturday.
Added Amy Thurlow, president, Dick Clark Prods.: "Tina and Amy have provided Golden Globes viewers with some of the most memorable moments the show has ever seen", said Amy Thurlow, President of dick clark productions.
"There are no two funnier people anywhere", Poehler joked. At the time, they claimed it would be the last time they hosted.
They replace Ricky Gervais, who hosted this year. Since Poehler and Fey last hosted, the Globes have turned to Gervais (twice), Jimmy Fallon, Seth Meyers and the combo of Andy Samberg and Sandra Oh.
Their return as hosts promises a shift in energy from Gervais' performance Sunday at the 77th Golden Globes, widely criticized for its biting nihilism, in which even he joked he'd not be invited back.
The 2021 ceremony doesn't have a set date yet.
Fey, along with Robert Carlock, is co-creator and an executive producer of NBC's upcoming Universal Television-produced untitled comedy series starring Ted Danson as L.A.'s mayor.