The jury found Shelly Morita was subjected to sexual harassment and a hostile work environment. She was awarded $822,000 in compensatory damages and $2.5 million in punitive damages.
Morita sued Peters five years ago, alleging he fondled her at his Malibu home and climbed into bed with her in an Australian hotel during the 2005 filming of "Superman Returns."
Morita claimed that she couldn't find work in Hollywood after suing Peters because of his influence in the industry.
Peters produced several acclaimed films including "A Star is Born," "Flashdance," "The Color Purple," "Batman" and "Rainman."
Peters' attorneys plan to appeal the verdict.
The Associated Press contributed to this report.