U.K. Supreme Court Rules Trans Women Can’t Be Defined as Women
Decision follows a yearslong legal battle over protections for women and female-only spaces
By Gareth Vipers
Updated April 16, 2025 9:18 am ET
LONDON—Britain’s top court ruled only those born female can be considered women, a landmark judgment that excludes transgender women from the legal definition and paves the way for tighter limits on female-only spaces and services.
The decision Wednesday by the U.K.’s Supreme Court came after a yearslong legal fight over the definition of a woman in a 2010 equality law, and could have far-reaching implications for the protections and freedoms given to transgender women in the U.K.
“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 the court’s deputy president, Lord Hodge.
The move marks a defeat for the Scottish government in its long-running battle with a women’s campaign group over the definition and legal protections for women and female-only spaces.
The Scottish government had argued that transgender people with a gender recognition certificate are entitled to certain protections and to access women-only areas. Its defeat could lead to greater restrictions on the rights of transgender women to use spaces and services reserved for women.
For Women Scotland, the campaign group that brought the case, argued that such access should only apply to people who are born female.
The dispute stems from a 2018 bill passed in the Scottish Parliament aimed at ensuring gender balance on public-sector boards. For Women Scotland said the bill had wrongly included transgender people as part of quotas and fought it under the U.K. equality act.
For Women Scotland co-founder Susan Smith welcomed the court’s decision but said the fight was likely to continue.
“Today the judges have said what we always believed to be the case, that women are protected by their biological sex, that sex is real and that women can now feel that services and spaces designated for women are for women,” Smith said while celebrating with supporters and activists outside the court in central London.
“What our politicians need to get their heads around is this is the law,” she added. “They need to stop putting faulty guidance into schools and hospitals.”
The U.K. Supreme Court sided with activists who argued that trans women shouldn’t have access to spaces and services reserved for women.
A spokeswoman for the Scottish government said that it accepted the judgment, but that it was important it wasn’t read as the triumph of one group over another.
“The ruling gives clarity between two pieces of relevant legislation passed at Westminster,” the spokeswoman said, referring to the U.K.’s parliament. “We will now engage on the implications of the ruling,” she added. In the U.K., some powers, such as over healthcare, are devolved to the national governments of Scotland, Wales and Northern Ireland.
“We want to reassure everyone that the Scottish Government is fully committed to protecting everyone’s rights,” the Scottish government spokeswoman said.
Scottish transgender charity Scottish Trans called for calm after the ruling. “We’d urge people not to panic—there will be lots of commentary coming out quickly that is likely to deliberately overstate the impact that this decision is going to have on all trans people’s lives,” it said in a social-media post Wednesday.
In the 88-page ruling, the judges said the concept of sex was binary, referring to either a woman or a man, and that they hoped the ruling would give clarity to the law while protecting both women and transgender people.
“The ordinary meaning of those plain and unambiguous words corresponds with the biological characteristics that make an individual a man or a woman,” the ruling read.
“These are assumed to be self-explanatory and to require no further explanation.”
Transgender rights groups argue that biological sex is more complicated than two binary categories, and some scientific researchers have backed calls for broader definitions. Some other Western countries have long recognized different frameworks. In 2013, Australia adopted guidelines saying people completing official forms should be able to choose male, female or “X.” Later that year, German lawmakers passed a law to allow parents to leave the gender blank on a child’s birth certificate.