Robin Wright threatened to out House Of Cards bosses if they did not give her equal pay to the show's male lead Kevin Spacey.
The actress stars as Claire Underwood, the scheming wife of US president Frank Underwood on the Netflix series, as well as being a producer and occasional director.
Speaking about the gender pay gap at the Rockefeller Foundation, she said she had to fight for the same wage as her co-star.
"I was like, 'I want to be paid the same as Kevin.'
"It was the perfect paradigm. There are very few films or TV shows where the male, the patriarch, and the matriarch are equal. And they are in House Of Cards," she told The Huffington Post.
She continued: "I was looking at the statistics and Claire Underwood's character was more popular than (Frank's) for a period of time. So I capitalised on it. I was like, 'You better pay me or I'm going to go public.' And they did."
According to Forbes, Robin made $5.5 million (£3.8 million) last year for her work on the show, which is now in its fourth series. Kevin reportedly received a pay rise to $9 million (£6.2 million) by the third series.
She also revealed how she felt she was having a comeback after stopping acting to raise her two children with then-husband Sean Penn made her "not box office material" in the eyes of producers.
She said: "Because I wasn't working full time, I wasn't building my salary bracket. If you don't build that ... with notoriety and presence, you're not in the game anymore. You become a B-list actor. You're not box office material.
"You don't hold the value you would have held if you had done four movies a year like Nicole Kidman and Cate Blanchett did during the time I was raising my kids. Now I'm kind of on a comeback at 50 years old."
Robin follows in the footsteps of actresses like Jennifer Lawrence who have spoken out about the gender pay gap in Hollywood.