The Oscar-nominated actress is set to play Judy Garland in both film and stage adaptations of Gerald Clarke's 2000 biography. It's titled "Get Happy: The Life of Judy Garland."
The announcement was made Monday by Weinstein Co. boss Harvey Weinstein.
The 26-year-old actress showed off her song-and-dance skills at last month's Academy Awards, where she sang with host Hugh Jackman.
Hathaway was nominated for an Oscar for her lead role in last year's "Rachel Getting Married."
Garland is perhaps best known for starring in 1939's "The Wizard of Oz" and singing its Oscar-winning ballad "Over the Rainbow." Other career highlights included an Oscar-nominated turn in the 1954 musical remake of "A Star is Born." She died in 1969 at age 47.