The Supreme Court of the United Kingdom in a landmark judgement ruled on Wednesday that the term “woman” in the Equality Act 2010 refers strictly to biological females, and not transgender women. The unanimous verdict by five judges is expected to have widespread implications for single-sex services such as domestic violence shelters, hospital wards, and sports facilities.
“The unanimous decision of this court is that the terms ‘woman’ and ‘sex’ in the Equality Act 2010 refer to biological women and biological sex,” said Deputy President of the Supreme Court, Justice Patrick Hodge. “We counsel against reading this judgment as a triumph of one or more groups in our society at the expense of another. It is not.”
The ruling marks a significant setback for transgender rights campaigners and has reignited public debate over the legal interpretation of sex and gender. Legal experts suggest it may influence future decisions involving equal pay, access to sex-segregated services, and hiring practices under diversity mandates.
However, the court clarified that transgender individuals remain protected under the act—but under the distinct characteristic of “gender reassignment,” not sex. “Transgender people continue to be protected against discrimination,” the judges stressed.
The case was brought by For Women Scotland (FWS), a gender-critical campaign group that opposed the Scottish Government’s inclusion of trans women—those with a Gender Recognition Certificate (GRC)—in official definitions of women for public sector equality duties. The court sided with FWS, effectively rejecting the Scottish Government’s stance that anyone legally recognised as female via a GRC qualifies as a woman under the Equality Act.
“This case has protected the rights of women and girls across the UK,” said JK Rowling, author of the Harry Potter series and vocal supporter of FWS.
The legal challenge stemmed from a 2018 Scottish initiative to increase female representation in public bodies, which extended eligibility to trans women with GRCs. FWS argued that the move diluted the intention of the act, which they said was meant to safeguard spaces and opportunities for biological women.
Aidan O’Neill KC, counsel for FWS, urged the court to prioritise “the facts of biological reality rather than the fantasies of legal fiction.”
LGBTQ+ groups warned the decision could restrict trans women’s access to women-only spaces, such as shelters and health services. The UK government, meanwhile, welcomed the judgment, saying it “brings clarity and confidence” to service providers.
Although centred on the legal recognition of women, the court’s interpretation of “sex” as “biological sex” also applies to transgender men—those who were born female but have transitioned—under the same legal framework.
