The actress explained to InStyle that being cast as Cosette in director Tom Hooper's musical adaptation gave her the defining role of her career thus far.
"The moment I auditioned for [Tom Hooper], everything changed," Seyfried revealed.
She added of working with Hooper: "He gunned for me. What's most important to him is an actor who can get it and who can be grounded enough to make it believable when she bursts into song."
Seyfried has received wide critical praise for her portrayal of Cosette, earning both Satellite and National Board of Review award nominations.
Watch a clip from the film below: