Evangeline Lilly Joins The Hobbit Cast

 Mike Marsland/WireImage.com

Lost alum Evangeline Lilly is headed to the big screen.

The actress, 31, will play the Woodland Elf, Tauriel in The Hobbit, director Peter Jackson announced on Facebook Sunday.

PHOTOS: Lost stars, then and now

"Her name means 'daughter of Mirkwood' and, beyond that, we must leave you guessing! (No, there is no romantic connection to Legolas.) What is not a secret is how talented and compelling an actress Evangeline is," Jackson raved. "We are thrilled and excited she will be the one to bring our first true Sylvan Elf to life."

PHOTOS: Hot bodies of Lost

The exciting news comes less than a month after Lilly welcomed her first child, a boy, with boyfriend Norman Kali.

Jackson also announced that actor Barry Humphries, 77, will play the Goblin King. He and Lilly join Orlando Bloom, 34, Elijah Wood, 30, Sir Ian McKellan, 72, Cate Blanchett, 42, Christopher Lee, 89, Hugo Weaving, 51, and Andy Serkis, 47, who are all reprising their Lord of the Rings characters in the prequel.

The first of the two films, The Hobbit: An Unexpected Journey, hits theaters December 14, 2012. The second installment, The Hobbit: There and Back Again, will be filmed back-to-back with the first; it will arrive in theaters December 13, 2013.

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!