The actress, now 44, is the latest star to claim that the disgraced Hollywood producer made unwanted sexual advances towards her at the beginning of her career.
In a candid Instagam post, Beckinsale said that she had escaped the encounter "unscathed" after insisting that she had to leave because she had “school in the morning”.
The Underworld actress went on to claim that Weinstein couldn’t remember if he had “tried anything” with her when he asked her about the meeting years later.
“I was called to meet Harvey Weinstein at the Savoy Hotel when I was 17. I assumed it would be in a conference room which was very common,” she wrote on Twitter.
“When I arrived, reception told me to go to his room. He opened the door in his bathrobe. I was incredibly naive and young and it did not cross my mind that this older, unattractive man would expect me to have any sexual interest in him.
“After declining alcohol and announcing that I had school in the morning I left ,uneasy but unscathed.”
Talking about their run-in a few years later, Beckinsale added: “A few years later he asked me if he had tried anything with me in that first meeting .I realized he couldn't remember if he had assaulted me or not.”
Beckinsale said that she went on to “say no” to Weinstein “professionally” a number of times over the years, provoking him to “threaten” her.
“I said no to him professionally many times over the years-some of which ended up with him screaming at me calling me a c*** and making threats, some of which made him laughingly tell people oh "Kate lives to say no to me.””
Beckinsale went on to say that a friend of hers attempted to warn a young actress off of Weinstein, based on her encounter, only for the girl to relay the conversation to the producer.
“I had a male friend who, based on my experience, warned a young actress who said she was going to dinner with Harvey to be careful,” she wrote.
“He received a phone call the next day saying he would never work in another Miramax film; the girl was already sleeping with Harvey and had told him that my friend had warned her off.”
Stars including Rose McGowan, Ashley Judd, Gwyneth Paltrow, Angelina Jolie and Cara Delevingne have alleged that they were sexually harassed by Weinstein.
The Metropolitan Police confirmed on Thursday that it was assessing a sexual assault allegation made against the Hollywood film producer.