Supreme Court Upholds Biological Sex as Foundation for Fair Women’s Sports Competition

The Supreme Court has affirmed what is widely recognized: Girls deserve fair competition, not paperwork tricks or activist slogans presented as inclusion.

In a decisive ruling Tuesday, the court settled the most consequential legal question in women’s sports for a generation—confirming that women’s sports must remain protected spaces for female athletes.

The court ruled 9-0 that Title IX, the federal law ensuring equal opportunities for women in education and sports, supports state laws protecting female athletes through sex-based categories. Additionally, the Equal Protection Clause was upheld 6-3 to allow states to safeguard these categories.

The landmark decisions in Little v. Hecox and West Virginia v. B.P.J. mark a turning point. The court established that sex is a biological fact, not an emotion, and that it shapes athletic performance in ways no policy can alter.

Writing for the majority, Justice Brett Kavanaugh held that Title IX “cannot plausibly be interpreted to refer to anything other than biological sex.”

By upholding state laws that protect sex-based categories in athletics, the court has reinforced the rights of girls and women in 27 states where such legislation already exists. This ruling ensures that biological males will no longer dominate girls’ shot-put competitions in West Virginia next season.

The majority opinion underscores immutable biological differences in strength, speed, and physiology, rejecting claims that gender identity can override sex in physical sports.

However, the victory remains incomplete as 23 states—including California—still permit biological males to compete in women’s categories. This patchwork of laws means fairness is geographically inconsistent.

The recent executive order from President Trump in 2025 provided critical momentum, prompting the NCAA to reaffirm that women’s sports are for women. The International Olympic Committee has committed to protecting female categories starting with the 2028 Los Angeles Games. Ballot initiatives in blue states like Colorado and Washington this November will let voters decide whether girls deserve their own sports. In Maine, fathers have mobilized to put a ballot initiative on the table for girls’ sports.

Despite these developments, challenges persist. The NWSL and WNBA continue without meaningful sex verification protocols, while professional leagues, private events such as the Boston Marathon, and college athletics remain fractured. Birth certificates—the only proof of sex required by the NCAA—can be changed in 44 states.

Blue states continue to disregard federal guidance, creating inconsistent competition scenarios across state lines. A female athlete protected in Tennessee could still face unfair qualification challenges against out-of-state males.

The deeper truth is that a Supreme Court ruling sets legal boundaries but cannot change culture alone. This work requires parents, athletes, coaches, journalists, and citizens to act with unrelenting clarity.

For too long, institutions have prioritized feelings over the safety and dignity of girls and women. The same pattern was observed in past gymnastics sex abuse scandals: Adults in power looked the other way while vulnerable athletes suffered.

The Safe Sport Act now exists to protect young athletes from abuse but faces a four-year backlog of reports.

Changing culture means rejecting the lie that biology is bigotry. It requires parents showing up at meetings with clarity, athletes speaking truthfully, sponsors and leagues facing consequences for unfairness, and raising a generation that understands sex is real and fairness is non-negotiable.

Legal victories are essential but not the finish line. We must build a culture where courage defeats compliance, evidence overcomes ideology, and protecting girls takes precedence over performative virtue.

Only then will Title IX—and fair sports—be fully realized for every daughter, in every state.

The fight continues. But today, with the Supreme Court’s backing, we have firmer ground beneath our feet.

Now let’s use it to shift the culture for good.

Jennifer Sey is the founder and CEO of XX-XY Athletics.