Peter Sarsgaard, Rosumund Pike, Emma Thompson, Olivia Williams and Carey Mulligan are already on board to star in the Lone Scherfig film.
An Education is a coming-of-age drama set in '60s London that sees a 17-year-old girl (Mulligan) swept off her feet by a thirtysomething man (Sarsgaard).
Bloom hasn't appeared on screen since last summer's Pirates of the Caribbean: At World's End.
Author Nick Hornby is writing the Education script based on Lynn Barner's autobiographical essay.
The film begins shooting in London next month.