Seyfried, 29, said the incident went down several years ago, and it's made her focus on gender equivalent compensation in the industry, reported Time.
"A few years ago, on one of my big-budget films, I found I was being paid 10 percent of what my male co-star was getting. And we were pretty even in status," she said.
Since her breakout moment in 2004's "Mean Girls", Seyfried has starred in an array of hit movies, including "Mamma Mia!" , "Dear John", "In Time", and "Les Miserables".