Caitlyn Jenner, who recently announced a California gubernatorial run, on Saturday came out against allowing transgender athletes who were born male to compete on girls' sports teams.

Jenner, a former Olympic athlete who famously came out as transgender in 2015, waded into a controversial issue that has sparked Republican-backed legislation in states across the country.

CAITLYN JENNER DISMISSES HOLLYWOOD NAYSAYERS AS SHE EMBARKS ON RUN FOR CALIF. GOVERNOR

"This is a question of fairness, that's why I oppose biological boys who are trans competing in girls sports in school," Jenner told TMZ. "It just isn't fair, and we have to protect girls sports in our schools."

Jenner is running as a Republican to unseat Democratic Gov. Gavin Newsom in an upcoming recall election in the deep-blue state.

Jenner's remarks come after the Florida legislature this week passed legislation that would restrict entry to girl's sports teams to those who were born female. Republican Gov. Ron De Santis has indicated that he will sign the bill.

West Virginia Gov. Jim Justice on Wednesday signed a similar bill, despite warnings that sports groups may protest by not holding college tournaments in the state. The NCAA in 2016 moved championships out of North Carolina in response to a bill about the gender-based use of sex-segregated bathrooms.

SEAN HANNITY TO INTERVIEW CAITLYN JENNER, DISCUSS HER BID FOR CALIFORNIA GOVERNOR

Trans activists have claimed that gender identity, rather than sex, should be the determination for who is allowed into which sports teams -- and called such bans cruel and discriminatory.

Opponents have pushed back, saying that it would be unfair for males -- however they may identify --  to be allowed entry into sports intended for girls and women, considering the differences between male and female bodies.

Bills seeking to ban transgender girls from competing on girls’ sports teams in public schools also have been enacted this year in Alabama, Arkansas, Tennessee and Mississippi, while South Dakota Gov. Kristi Noem has issued an executive order on the matter.

CLICK HERE TO GET THE FOX NEWS APP

Those state moves are pushing back against an executive order by President Biden, which allows student athletes to participate in accordance with their gender identity.

Fox News’ Sean Hannity will sit down with Jenner for an interview airing Wednesday at 9PM/ET.

The Associated Press contributed to this report.