The Harry Potter and Sense and Sensibility star said that the movie producer was just one “predator” at the top of a system full of people who exploit young women.
Weinstein, 65, has been fired from his production company and faces the possibility of criminal charges in the US and the UK.
His fall from grace came after a New York Times expose about his sexual harassment and sexual assaults of actresses and employees over three decades opened the floodgates to a string of accusations from leading actresses such as Gwyneth Paltrow and Angelina Jolie.
But the Oscar-winning actress has dismissed his claim that he will be seeking treatment for “sex addiction”.
Speaking to BBC Newsnight, she said: “I didn’t know about these things but they don’t surprise me at all and they’re endemic to the system anyway.”
“What I find extraordinary is that this man is at the top of a very particular iceberg. I don’t think you can describe him as a ‘sex addict’. He’s a predator. That’s different.
“But what he’s as it were the top of the ladder of is a system of harassment and belittling and bullying and interference and what my mother would have referred to in the olden days as ‘pestering’.”
“‘Is he pestering you?’ That’s the word we’ve used to use in the olden days, if you recall. This has been part of our world women’s world since time immemorial.”
She said it was important to start talking about “the crisis of extreme masculinity” which she said was at the heart of this sort of sexual harassment, where men feel the need to express their own power by dominating and sexually degrading women.
The 58-year-old said she thought Weinstein’s case was probably the most extreme but it was not isolated and there were “many, many” others.
Harvey Weinstein: his accusers
“Do they have to all be as bad as him to make it count? Does it only count if you really have done it to loads and loads and loads of women? Or does it count if you do it to one woman once. I think the latter,” she added.
The interview comes after reports emerged earlier this week that Thompson stood up to Weinstein on the set of the film version of Evelyn Waugh’s Brideshead Revisited in 2007, after he told her co-star Hayley Atwell she was too fat.
Weinstein had come to the set as his company, Miramax, was handling the US distribution rights. It was there that he met the then 24-year-old Atwell.
But after seeing her eating lunch he told her: “You look like a fat pig on screen. Stop eating so much.”
On hearing this Thompson reportedly told him she would quit halfway through shooting if he ever spoke to Atwell or any other woman on set like that again.
A source told the New York Post: “Emma called Harvey out for being a misogynist and a bully and really gave him a hard time.”