Argento, one of the women quoted in Ronan Farrow's New Yorker article in October, said Weinstein raped her during the Cannes festival in 1997 when she was 21.
Weinstein has denied allegations of non-consensual sex. A spokesman for Weinstein had no immediate comment. Argento's London-based agent, Steve Kenis, was not immediately available to provide further details.
"This festival was his hunting ground," Argento said in a speech ahead of the awarding of the Palme d'Or and other prizes.
She said Weinstein, until this year a hugely influential presence at the festival, would never return, "shunned by a film community that once embraced him and covered up for his crimes".
"Even tonight, sitting among you, there are those who still have to be held accountable for their conduct against women," she said.
"You know who you are, but, most importantly, we know who you are, and we are not going to allow you to get away with it any longer," she ended her speech, to applause.
Her statement reinforced the idea that this particular edition of Cannes arrives in a world awakened by the #MeToo movement. Earlier in the week, Blanchett, DuVernay Stewart, Seydoux, and Nin stood together with iconic French director Agnes Varda on the steps of the Palais in a demonstration for equal pay and recognition from the film industry. Of the three women directors in competition, two earned prizes from the jury, while the third, Eva Husson, had the distinction of making the film that ranked lowest among the critics polled by Screen Daily, Girls of the Sun.
Speaking up on behalf of the female-driven movie at the press conference, Blanchett called it "a powerful, wonderful film that all of us hope will be seen all over the world," adding, "By not choosing something, it doesn't mean we disregard it. It's a painful process."
Organisers of the festival also set up a telephone hotline for victims of harassment, and several discussion groups addressed the issues of sexual abuse and the under-representation of women in the film business.