The 50-year-old actress claimed that the 66-year-old movie producer kept her from a role in Lord of the Rings, and then blacklisted her from further movie roles, after she refused his sexual advances.
"The Court makes clear that it is not determining whether Plaintiff was sexually harassed in the colloquial sense of the term", he wrote in his decision. "The only question presented by the current motion is whether the harassment that Plaintiff allegedly suffered falls within the scope of the California statute that she has sued under".
Representatives for Ms Judd and Mr Weinstein could not immediately be reached for comment on the ruling.
"Ms Judd was hired for not one, but two of Mr Weinstein's movies, Frida in 2002 and Crossing Over with Harrison Ford in 2009".
Judd originally filed the suit in April 2018. She said Weinstein continued to "lord that traumatic event" over her and would mention their "little deal".
Despite tossing out the harassment claim, Judge Gutierrez gave Judd the greenlight on moving forward with a civil lawsuit on her defamation claim.
Despite "serious discussions to play a major role in the Lord of the Rings trilogy", court documents state, Judd wasn't cast in the film.
She also said Weinstein told director Peter Jackson and his producing partner, Fran Walsh, not to work with Judd on the films, CNN reported. He has denied all allegations of non-consensual sex.
"We have said from the beginning that this claim was unjustified, and we are pleased that the court saw it as we did".
He added: "While we respectfully disagree with the Court's decision as to the one claim it ruled on today, we look forward to pursuing the three claims for relief that the court has already ruled can move forward".
Judd's attorneys argued that the legislative amendment should apply retroactively, allowing Judd's sexual harassment claim to proceed.
Jackson confirmed in December 2017 that Weinstein had in the 1990s sought to discredit actresses who later went on to accuse him of sexual misconduct.
The disgraced producer - who denies the charges, which were brought by two women - will stand trial in NY later this year.
The disgraced movie mogul faces a variety of sexual misconduct and sexual assault accusations from more than 60 women, including such stars as Mira Sorvino, Gwyneth Paltrow, Rose McGowan and many others.