The Hatfields & McCoys actor takes over the role after Sam Claflin had to exit the project due to a date clash with The Hunger Games: Catching Fire, reports Deadline.
Last month, Claflin joined the Hunger Games sequel as Finnick Odair, after much casting speculation.
Reid now will play Claflin's former Belle role as John Daviner.
Directed by Amma Assante, Belle recounts the true story of aristocrat Dido Elizabeth Belle Lindsay (Gugu Mbatha-Raw), a mixed-race girl who fell in love with Daviner.
The upcoming drama also stars Tom Felton, Tom Wilkinson, Emily Watson, Matthew Goode, Miranda Richardson, Sarah Gadon, Penelope Wilton and James Norton.
Red was previously seen in the western mini-series Hatfields & McCoys, featuring Kevin Costner and Bill Paxton.
Watch Jennifer Lawrence talk to Digital Spy about The Hunger Games below: