The pair married September 2007, and the documents say they separated Nov. 22.
The couple have no children together.
The 41-year-old actress is the star of the "Grey's Anatomy" spin-off "Private Practice" on ABC. Young is a top-ranking executive at 20th Century Fox.
The pair released a joint statement through the publicists saying the split was amicable and that Walsh and Young remain friends.
The breakup was first reported on a Web site for "The Insider" TV show.
