The Sun reports the Titanic star was urged to thank powerful producer Weinstein if she won Best Actress for her role in 2008 film The Reader.
But, refusing to bow to pressure, 42-year-old Winslet thanked some 19 people - and "deliberately" left out the film's disgraced producer.
Speaking to the LA Times, she said: "I remember being told, 'Make sure you thank Harvey if you win.'
"And I remember turning around and saying, 'No I won't. No I won't.'
"And it was nothing to do with not being grateful. If people aren't well-behaved, why would I thank him?
"But that's how he operated. He was bullying and nasty."
"The fact that I'm never going to have to deal with Harvey Weinstein again as long as I live is one of the best things that's ever happened and I'm sure the feeling is universal."
In a wideranging interview, Winslet went on to describe how Weinstein would regularly remind her that he had given her a start in the movie business.
She added: "For my whole career, Harvey Weinstein, whenever I've bumped into him, he'd grab my arm and say, 'Don't forget who gave you your first movie.' Like I owe him everything."
The prolific producer was until recently considered one of the most powerful figures in Hollywood.
But a string of sexual assault and harassment allegations have seen dozens of women - many of them actresses - accuse Weinstein of acting inappropriately towards them.
Several have alleged they were raped by the 65-year-old.
Stars including Gwyneth Paltrow, Angelina Jolie and Kate Beckinsale have alleged they were the victims of Weinstein's sexual advances.