Three time Olympic swimming gold medallist Nancy Hogshead is calling on the WNBA to clearly define who qualifies as a woman under its player eligibility rules.

Hogshead launched a petition in August urging the league to adopt explicitly female only eligibility criteria. The petition has surpassed 21,000 verified signatures.

The campaign focuses on the WNBA's 2026 collective bargaining agreement, which states that “only players who are women are eligible to play in the WNBA.” Hogshead argues that the league should clearly define the term “woman” and establish transparent eligibility standards.

She has received support from figures including tennis legend Martina Navratilova, former NBA player Charles Barkley and former basketball player Enes Kanter Freedom. Republican lawmakers have also written to WNBA Commissioner Cathy Engelbert seeking clarification of the league's policy.

The WNBA has said there are currently no immediate eligibility matters involving the issue and has criticised attempts to use the debate to demean or marginalise people.

The controversy comes amid a wider international debate over transgender participation in women's sport, with sporting organisations increasingly reviewing their eligibility policies.

For Hogshead, the issue is ultimately about ensuring that the WNBA's rules clearly establish the criteria for participation in its women's competition.