The story revolves around Rachel, who constructs a make-believe perfect life for a couple she sees every day from her window on the train-until one day when she involves herself in their real-life drama, reported TIME.
The film, to be directed by Tate Taylor will see Blunt, 32, playing the lead role.
"The Girl on the Train" has sold more than two million copies in the US, since its debut in January, making it the fastest-selling adult novel of all time.