The U.S. Supreme Court has issued a landmark decision allowing states to continue protecting girls’ and women’s sports by requiring athletes to compete based on their biological sex at birth.

In a closely watched ruling Thursday, the justices sided with West Virginia and Idaho in two cases challenging state laws that restrict biological males from competing in female athletic competitions. The decision establishes a nationwide precedent affirming that states may designate school sports teams based on biological sex rather than gender identity.

The cases, West Virginia v. B.P.J. and Little v. Hecox, centered on West Virginia’s Save Women’s Sports Act and Idaho’s Fairness in Women’s Sports Act. Both laws had previously been blocked after legal challenges brought by transgender athletes represented by the American Civil Liberties Union (ACLU) and Cooley Legal. The states were represented by Alliance Defending Freedom (ADF).

West Virginia Attorney General John McCuskey hailed the ruling as “a monumental victory for every female athlete who has ever competed, or dreamed of competing, on a fair and safe playing field.”

“Today’s Supreme Court decision affirms what common sense and the law have long made clear: states have the right to designate sports teams based on biological sex, not gender identity,” McCuskey said. “Without that delineation, Title IX is turned on its head and decades of hard-fought progress to advance female athletes is erased.”

Idaho Attorney General Raul Labrador likewise celebrated the decision, calling it “a victory for common sense, fairness, and the countless girls and women who dedicate themselves to athletics.”

“The Supreme Court has now confirmed that states can preserve fair competition and protect the opportunities that generations of women fought to secure,” Labrador said. “Every parent can rest assured that our law protects their daughters competing in Idaho.”

The ruling follows oral arguments heard by the Court in January after it agreed last year to hear both cases. The decision is expected to strengthen similar laws already passed in 27 other states, providing greater legal certainty for lawmakers who have sought to preserve separate athletic competitions for women and girls.

The plaintiffs included Lindsay Hecox, who sought to compete in women’s track and cross-country at Boise State University, and Becky Pepper-Jackson, a transgender athlete from West Virginia who challenged the state’s law in 2021.

During oral arguments, Chief Justice John Roberts questioned attorneys about the legal definition of sex. After initially urging the Court not to define the term, ACLU attorney Joshua Block ultimately acknowledged that, for purposes of the case, the Court could accept biological sex as the relevant definition.

The Court’s decision is likely to remain at the center of the national debate over sex, gender identity, and athletics. While more than half of U.S. states now have laws protecting women’s sports, others—including California, New York, and Massachusetts—continue to permit transgender athletes to compete based on gender identity.

For many Christian organizations and advocates of women’s sports, Thursday’s ruling represents a significant affirmation of biological reality and the principle of fairness in athletic competition. As legal and cultural debates continue, many believers see the decision as an opportunity to uphold both truth and compassion while engaging difficult issues with wisdom and grace.