Damon told ABC News he “knew the story about Gwyneth” from Ben Affleck, referring to Gwyneth Paltrow's claims that Weinstein sexually harassed her in a hotel room.
“I never talked to Gwyneth about it. I knew that they had come to whatever, you know, agreement or understanding that they had come to. She had handled it,” he said.
"When people say like, 'Everybody knew,' Like, yeah," he continued. "I knew he was an a------."
"I knew he was ... a womaniser," Damon added. "I wouldn't want to be married to the guy. But ... the criminal sexual predation is not something that I ever thought ... was going on. Absolutely not."
Clooney revealed that Weinstein had bragged to him about having affairs with actresses who were friends of his.
"I didn't really think that they were going to have affairs with Harvey, quite honestly. And clearly they didn't," he said.
"But the idea that this predator, this assaulter ... was out there silencing women like that, it's beyond infuriating."
Both actors say they had no idea of the sexual assault or harassment which has been alleged by over 30 women, saying that had they known they would have done something.
"There has to be a comeuppance for all of this," Clooney said. All of the people who are part of that chain. We have to make it safe for people to feel that they can talk about this. And in doing that, I think that'll scare away that kind of behaviour."