Oh, 34, filed a petition for divorce Friday in Los Angeles Superior Court and asked for spousal support.
She and Payne, 44, were married in January 2003 and have no children, court records said.
The couple met five years ago and announced their separation last month.
Payne won an Oscar for the screenplay of "Sideways," (search) about two friends' wine-tasting trip through Santa Barbara County vineyards. He also directed "Election," "About Schmidt" and "Citizen Ruth."
Oh stars in ABC's television series "Grey's Anatomy." (search)