Judd had accused Weinstein of defaming her in 1998 after she refused what she said were his sexual advances a year earlier.
In her lawsuit, filed in April 2018, the "Double Jeopardy" actress accused Weinstein of smearing her reputation by discouraging director Peter Jackson from casting her in his blockbuster movie franchise "The Lord of the Rings."
Judd, one of the first women in October 2017 to publicly accuse Weinstein of sexual misconduct, had accused the Hollywood movie mogul of sexual harassment in violation of a California law barring such conduct by a person in a "business, service or professional relationship" with another.
In a footnote to his ruling, US District Judge Philip Gutierrez said he was not determining whether Judd was sexually harassed by Weinstein "in the colloquial sense of the term."
But Gutierrez said that Judd's relationship as an actress with the film producer was not covered under the California statute she had sued under, nor under a 2019 amendment.
“We have said from the beginning that this claim was unjustified, and we are pleased that the court saw it as we did. We believe that we will ultimately prevail on her remaining claims,” Weinstein's lawyer, Phyllis Kupferstein, said in a statement.
But Judd's attorney, Theodore J. Boutrous, Jr., said that this ruling does not upend Judd's complaint.
“Nothing about today’s ruling changes that Ms. Judd’s case is moving forward on multiple claims," Boutrous said in a statement late Wednesday.
"We look forward to pursuing the three claims for relief that the Court has already ruled can move forward,” he also said.