The ex-movie mogul was on his way to Los Angeles on Tuesday to appear for further assaults in a second trial.
Since March 2020, he has been serving 23 years in prison for rape and sexual assault in New York.
The 69-year-old former producer left Wende prison in upstate New York on Tuesday, shortly before 9:30 a.m., before being handed over to California authorities.
Harvey Weinstein is accused in California of rape and sexual assault on five women.
The former Hollywood almighty faces up to 140 years in prison, in addition to his New York conviction, and could be brought before a judge as early as Wednesday morning.
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"Today Harvey Weinstein was taken to Los Angeles," city police said on Twitter.
"After passing a medical examination, he will be taken into custody with the county sheriff."
Lawyers for the ousted magnate had pleaded for weeks against this transfer, in particular for medical reasons.
But New York judge Kenneth Case rejected their arguments and gave the green light on June 15.
The legal procedures undertaken from Los Angeles to avoid this extradition were also unsuccessful.
A trial expected by mid-November
"We are disappointed", assured a spokesperson for Harvey Weinstein to AFP, while assuring that she would continue to fight so that the ex-producer "receives his medical treatments and of course, that he is treated fairly ”.
Under California law, Weinstein's trial must begin within 120 days of this transfer, or by mid-November.
Read also Harvey Weinstein in prison: why he avoided the worst
In Los Angeles, Harvey Weinstein is notably accused of having raped a female Italian model in a Beverly Hills hotel in February 2013, then of having sexually assaulted Lauren Young, an aspiring actress, in the bathroom of another. hotel.
He has always denied the facts, in New York and Los Angeles, claiming his accusers consented.
In early April, he formally appealed his conviction for rape and sexual assault in New York, which was imposed on him in March 2020 after a resounding trial for victims of the #MeToo movement. In total, nearly 90 women have accused Harvey Weinstein of sexual harassment or assault.