It was announced back in February that 12 year old French-Canadian youngster Sophie Nélisse landed the role and with filming now complete, the film is scheduled for release in November.
Director Brian Percival described the casting search to USA Today. He knew it was crucial to find the right actress to play Liesel Meminger, but after seeing "thousands" of actresses from around the globe, Percival was stuck as he prepared for the film.
"Some were good in different ways but nobody was actually Liesel," he says. "And it was key that we found someone who didn't have to act it so much as just be Liesel."
"It was quite uncanny, this kid. I was taken right away," says Percival. "It was this mixture of naive innocence but at the same time she's actually quite ballsy. You feel that you can get kneed in the groin at any point."
"It's a big ask to have someone that age carry such a key role. If Sophie didn't get it right, everyone else would have struggled around her, fortunately, she just nailed it." said Percival.
Even though she starred in 2011's Monsieur Lazhar, Oscar-nominated for best foreign film, Nélisse described accepting the Book Thief role as daunting.
"There were so many big actors (already cast) I thought they'd say, 'Oh, she's not very good.' " said Nélisse, who turned 13 during filming. "But after the first week they found that I was not that bad!"
Nico Liersch plays Rudi Steiner, Liesel's best friend described as having a heart of gold and a lust for life.
Ben Schnetzer, and American actor trained at Guildhall drama school in London, stars as the refugee Max who Liesl befriends.
The Book Thief is due for release this November.