The live-action film will be based on the fantastical tale of a Big Friendly Giant who befriends a young orphan girl. Dahl's book, illustrated by Quentin Blake, was first published in 1982.
DreamWorks acquired the book in 2011 with Kathleen Kennedy and Frank Marshall to produce. Various directors have been attached to the project over the years, including John Madden and Chris Columbus.
Melissa Mathison, who penned the script for E.T., wrote the screenplay. Marshall will produce with Michael Siegel on board as executive producer along with Madden. (Kennedy is now running Lucasfilm and busy producing the new Star Wars movies.)
Spielberg is officially committing himself to BFG and is planning a 2015 start date with a release in 2016.