Trans women aren’t legally women: What the UK Supreme Court ruling means

The ruling concluded a long-running dispute between feminist advocacy groups and the Scottish government.

The United Kingdom’s Supreme Court has ruled that the terms “woman” and “sex” refer to a “biological woman and biological sex” under UK equality laws, bringing a long-running court battle between feminist groups and the government of Scotland to an end.

Wednesday’s ruling is expected to have far-reaching consequences for policies on whether and how spaces and services reserved for women should be extended to include “trans women” – those born male who have transitioned socially or medically or who identify as women – such as changing rooms, domestic violence shelters and medical services.

Although the case originally began in Scotland, the court’s interpretation of the law will be effective across the UK, including in England and Wales.

Reactions towards the ruling have been mixed: Feminist advocacy groups involved in the legal case have voiced satisfaction, while trans groups and some members of the Scottish government expressed disappointment and fear about future discrimination.

Here’s what we know about the Supreme Court’s ruling and how the case started:

UK supreme court ruling
Marion Calder and Susan Smith from For Women Scotland celebrate outside the Supreme Court to challenge gender recognition laws, in London, UK, Wednesday, April 16, 2025 [Kin Cheung/AP]
What was the case about and how did it start?
The legal dispute began in March 2018 when the Scottish Parliament passed an act stating that 50 percent of non-executive members of the boards of Scottish public bodies must be women.

The act, which is known as Holyrood’s Gender Representation on Public Boards (Scotland) Act 2018, was supposed to ensure better representation for women in public bodies.

A sticking point in the policy, however, was the definition of “woman”. The act itself said that “women” included transgender women who held gender recognition certificates (GRCs) – that is, trans women who have legally transitioned and are certified by the government as having changed their gender.

A feminist group, For Women Scotland (FWS), challenged the new law and launched a petition against it in 2018. The group argued that the Scottish parliament had wrongfully defined “woman” and that the law had failed to use legal definitions as set out in the UK Equality Act of 2010.

That Act prohibits discrimination based on age, disability, gender reassignment, marriage or civil partnership (in cases of employment), pregnancy and maternity, race, religion or belief, sex, and sexual orientation.

However, the UK Equality Act 2010 does allow for separate or single-sex services to be provided when this is reasonably necessary, such as for reasons of privacy, decency or preventing trauma.

A Scottish court dismissed the first case brought by FWS in 2022, concluding that the Scottish legislation did not necessarily redefine “woman” by including transgender women. The judge ruled that women were “not limited to biological or birth sex”.

FWS launched an unsuccessful appeal in 2023. The case was then heard at the Scottish Court of Session several times as the group sought to clarify how to correctly interpret the term “woman” as enshrined in the Equality Act.