Catherine Zeta Jones Cast in Rock of Ages

Catherine Zeta-Jones is prepping to go back to work -- and rock out!

The Oscar-winning actress, 41, has officially joined the all-star cast of Rock of Ages, the big-screen adaptation of the hit, hard-rock Broadway musical, a source confirms to Us Weekly. (Hollywood Reporter first broke the news that Zeta-Jones was in final negotiations for the film.) Directed by Adam Shankman, the flick previously nabbed Tom Cruise, Alec Baldwin, Paul Giamatti and Mary J. Blige for its cast.

PHOTOS: Catherine and other stars who had pregnant Oscar nights

"It's a new character created just for the screen," the source tells Us. "She's playing the mayor's wife...Basically she's the villain of the film. She wants to get rock and roll out of Los Angeles!"

PHOTOS: Oscar winners then and now

Last week, Zeta-Jones briefly checked into a mental health facility to get treated for bipolar II disorder, her rep confirmed to Us. Zeta-Jones stood by husband Michael Douglas' side as he battled cancer. The duo have two kids together: son Dylan, 10, and daughter Carys, 7.

PHOTOS: Celebrity rehab centers

"Catherine is a hard-working actress, beautiful and talented. You never hear a bad word about her," the insider says. "And she won an Oscar for Chicago, a musical. This is perfect for her."