Emily Blunt is also set to join the cast. Cedric Nicolas-Troyan is directing the film, reported Variety.
The film reveals how the fates of two characters, the Huntsman Eric (Hemsworth) and Ravenna, intersected before they met Snow White. Details on 37-year-old Chastain's character are vague.
Frank Darabont, who was previously attached to direct before falling off, wrote the current draft of the screenplay, with earlier drafts by Craig Mazin and Evan Spiliotopoulos.
The film is set to bow on April 22, 2016. Universal's vice president of production Maradith Frenkel and creative executive Chloe Yellin will oversee the project for the studio.