One of the biggest producers in Hollywood, Mr Weinstein was behind films including Shakespeare in Love, The King’s Speech and Pulp Fiction.
The Weinstein Company directors said that “in light of new information about misconduct” his employment had been terminated “effective immediately”.
Mr Weinstein had been informed.
His sudden departure comes after the New York Times published a report last week about sexual harassment claims dating back nearly three decades.
The 65-year-old apologised and said he planned to take a leave of absence.
“The way I’ve behaved with colleagues in the past has caused a lot of pain, and I sincerely apologise for it,” Mr Weinstein said.
However, he later disputed the report, which said he had reached at least eight settlements with women, and vowed to take legal action.
Mr Weinstein is one of the most powerful men in Hollywood, having co-founded the Miramax and Weinstein Company production firms.
The allegations against him, according to the New York Times report, emerged mainly from young women hoping to break into the film industry and included celebrities Ashley Judd and Rose McGowan.
The accusers said the film producer forced them to massage him and watch him naked. In return for sexual favours, he promised to help advance their careers, they said.
President Donald Trump said on Saturday he was “not at all surprised” by the revelations about Mr Weinstein, a major backer of Democratic candidates.
Many Democratic lawmakers have since vowed to give their contributions from Mr Weinstein to charity. Mr Trump faced his own sex scandal last year when video emerged of him using lewd language to describe groping women.
Mr Weinstein, who is married to English fashion designer Georgina Chapman, formed the Miramax production house in the late 1970s with his brother and then sold it to Disney.
The pair went on to create The Weinstein Company and produce such hits as Django Unchained, Lion and The Butler.
The Weinstein Company statement was issued on Sunday by the firm’s all-male board, Bob Weinstein, Lance Maerov, Richard Koenigsberg and Tarak Ben Ammar.
His departure leaves control of the company in the hands of his brother, Bob Weinstein, and chief operating officer David Glasser.
Actress Rose McGowan called on the Weinstein board to resign immediately over the allegations.
“Men in Hollywood need to change ASAP,” she told The Hollywood Reporter. “Hollywood’s power is dying because society has changed and grown, and yet Hollywood male behaviour has not.”
Last week Mr Weinstein’s lawyer, Lisa Bloom, said that he denied many of the allegations made against him as “patently false”.
“He has acknowledged mistakes he has made,” said Ms Bloom. “He is reading books and going to therapy. He is an old dinosaur learning new ways.”
But on Saturday, Ms Bloom said in a tweet that she was no longer advising Mr Weinstein.
“I have resigned as an advisor to Harvey Weinstein,” the tweet said. “My understanding is that Mr Weinstein and his board are moving to an agreement.”