The IOC and Transgender Women’s Sport
By Prof Dr Ian Blackshaw
In two previous recent Posts on this website, we have reported on the issue of transgender women athletes participating in women’s sports events in the light of the UK Supreme Court ruling, on 16 April 2025, which held that the legal definition of a woman is based on biological sex and that the "concept of sex is binary" and, also held that a person with a Gender Recognition Certificate in the female gender "does not come within the definition of a woman".
We also reported that the first UK sports body to change its eligibility rules, as a result of the UK Supreme Court ruling, was the Ultimate Pool Group (UPG), who organise and promote professional 8-Ball Pool events in which the world’s top players participate. Under their new rules, which came into effect on 23 April, UPG women's events will be "open only to biologically born women" and also that transgender women will no longer “be eligible to be selected for international events in the female category.”
However, what effect will these developments have on the position adopted, to date, by the International Olympic Committee (IOC), which is widely considered as ‘the pinnacle of sport’?
To a certain extent and for some time, the IOC has ‘sat on the fence’ on the issue of transgender females competing in women’s sporting events. Currently, the IOC leaves it to individual Olympic sports bodies to decide for themselves how best to balance the need for inclusion and fairness in their sports.
Apart from the UK Supreme Court ruling, mention may be made of the recent Court of Arbitration for Sport (CAS) ruling in the case of the US transgender Pennsylvania University swimmer, Lia Thomas. She unsuccessfully challenged, on the grounds of discrimination, contrary, amongst other legal instruments, to the Olympic Charter (see ‘Fundamental Principles of Olympism’), the World Aquatics 2022 ban on transgender women participating in their female events. The three-member CAS Panel unanimously held, on 10 June 2024, that Thomas had no legal standing to bring the case and, therefore, dismissed it (CAS 2023/O/10000). However, it will be noted that this challenge by Lia Thomas was dismissed on procedural grounds rather than on its merits.
In the light of the UK Supreme Court ruling, which, of course, is not legally binding on the IOC, which is based in Lausanne and subject to Swiss Law, perhaps the new IOC President, Kirsty Coventry, an Olympic swimmer herself, may grasp the nettle and lay down some clearer rules for its 206 accredited National Olympic Associations to follow on the thorny issue of protecting the female category in sport. Such decisive action would be in line with the current climate in sporting circles, as evidenced by bans already issued, in addition to World Aquatics (mentioned above), and, amongst others, by World Athletics, whose President, Lord Sebastian Coe, has called for improved IOC rules. Such rules would also chime with public opinion generally, in relation to which a 2025 study by the British polling organisation ‘YouGov’, revealed that only 32% of the British public support transgender women being allowed to participate in women's sporting events.
The IOC will, no doubt, be mindful that any new rules must also make appropriate provisions for transgender women to be able to compete in an open category in their respective sports, in accordance with the fundamental aims of inclusiveness and fairness in sport, as laid down in the Olympic Charter.
Prof Dr Ian Blackshaw may be contacted by e-mail at ‘
