The participation of transgender athletes in sex-based sports has be-come one of the most politically and culturally fraught issues of our time. As of May 2024, twenty-five states have passed laws or regulations that categorically prohibit transgender women and girls in K-12 schools and/or college from playing sex-based sports with other women and girls. Like so many areas of transgender people’s lives—from access to healthcare to use of public restrooms—participation in sex-based sports is now a legal issue that will be decided by courts. Debate over the prop-er legal response to the participation of transgender athletes in sex-based sports has focused almost exclusively on sex discrimination law. This Article offers a different but complementary way to address the cat-egorical exclusion of transgender women and girls from sex-based sports based on a source of civil rights that has been noticeably missing from the current debate: disability rights law.

“Gender dysphoria” is the clinically significant distress a transgender person experiences if they are not allowed to live as who they are. For over thirty years, the Americans with Disabilities Act and the Rehabilitation Act have excluded from their protection “gender iden-tity disorders not resulting from physical impairments.” In recent years, numerous federal courts and agencies have interpreted these laws to prohibit discrimination based on gender dysphoria, culminating in the Fourth Circuit’s landmark decision in Williams v. Kincaid in 2022—the first circuit-level case to recognize gender dysphoria as a protected disa-bility under disability rights laws. Accordingly, state laws that categori-cally ban transgender women and girls from playing sex-based sports discriminate based on gender dysphoria in violation of disability rights law.