"I think he sexually assaulted a child and I don’t think that’s right," the actress said during Variety and Kering’s Women in Motion talk, alongside her Thelma & Louise costar Geena Davis.
"I have nothing good to say about him," she added. "I don’t want to go there."
Controversy surrounding Allen has swirled at the festival since opening night, when his new film Café Society premiered. Ronan Farrow, the director's son with Mia Farrow, wrote a column in The Hollywood Reporter about his sister Dylan's allegations that Allen sexually abused her as a child. In the article, Ronan condemned the media for not asking Allen tough questions, and called out stars for continuing to work with the director, comparing the situation to Bill Cosby.
Allen has long denied the allegations, writing in The New York Times in 2014, "of course, I did not molest Dylan." In 1993, a Connecticut prosecutor decided not to pursue charges against Allen because, he said, Dylan was too "fragile" for a trial.
He also addressed Ronan's article during interviews on Thursday, telling WHO and a small group of reporters, "I've said everything I have to say about the whole situation in The New York Times. I have so moved on. I never think about it. I work and do my movies."
"I just think it's so silly, the whole thing," he added, according to The Washington Post.
He later admitted he hasn't read Ronan's essay, telling Variety: "I never read anything. I never read what you say about me or the reviews of my film. I made the decision I think five years ago never to read a review of my movie. Never read an interview. Never read anything, because you can easily become obsessed with yourself."
The director also became the center of attention during the opening night ceremony, when according to Variety, French comedian and emcee Laurent Lafitte joked, "It's very nice that you've been shooting so many movies in Europe, even if you are not being convicted for rape in the U.S."
Lafitte has since claimed the joke was misinterpreted, telling The Hollywood Reporter that Roman Polanski was actually its intended target.