The 24-year-old Brit stars in the Sundance hit ''An Education''

By EW Staff
August 14, 2009 at 04:00 AM EDT

How You Might Know Her: Mulligan, 24, played one of Keira Knightley’s little sisters in 2005’s Pride & Prejudice.
Her New Film: In the Sundance hit An Education, Mulligan stars as a 1960s London student who falls for a posh older man (Peter Sarsgaard) and quickly finds herself in over her head, both socially and emotionally.
Her Big Moment: Though Mulligan was 22 at the start of shooting, she’s entirely convincing as a 16-year-old. ”I’d walk on set in the gray school uniform with no makeup on and my side parting,” she says. ”I could just be a silly schoolgirl again.”
Release Date: October 9