Liberal Democrats have backed a motion calling for all schools to have gender neutral uniforms for students.
Campaigner Jess Install, 15, said allowing girls to wear trousers and boys to wear skirts could result in happier students, better exam results and even better jobs.
Speaking at the Scottish Liberal Democrats conference in Dunfermline, she said: “It’s a small step forward but it will make a huge difference.”
Her call was backed by the party’s UK deputy leader, Jo Swinson, who recalled how she had campaigned for girls to be allowed to wear trousers when she was a student at Douglas Academy in Milngavie.
Ms Swinson said: “There is an important principle here about not segregating boys and girls according to gender.
“There’s also practicalities. I read about a school where primary school girls were told they weren’t allowed to turn cartwheels in the playground because it was ‘unladylike’. As if we send our little girls to primary school to learn how to be a lady.”
Party members at the conference backed a motion calling on the Scottish Government to require schools to provide “inclusive, non-prescriptive gender neutral school uniform policies”.
In her speech, Ms Install hit out about the “harm that sexist uniforms are doing to young girls”.
The teenager said: “I’m not telling anyone to take away their skirts, I’m telling you all that pupils should have the freedom to dress appropriately for their personal identity regardless of their gender.”
She added: “Is it really acceptable that we dictate the way our children dress based on only their gender - or in many cases the gender that society forces them to conform to.”
She argued that giving girls “more practical uniform options” could help encourage greater physical activity, and spoke out about the “harmful gender stereotypes that sexist uniform policies promote”.
The schoolgirl said: “The minute a girl walks into a primary school she is shown that the boys have more freedom to run about, she is told while she has to wear a skirt the boys don’t, she is told to take inequality for granted and to respect it as the norm.”
She added: “Gender neutral school uniforms teach our young people to be more open and accepting to those who are different.
“It teaches them to be tolerant not only towards their classmates, but towards their neighbours, teachers, friends and family. It ensures all pupils are equal regardless of their gender.
“Gender neutral uniforms will make a real impact on pupils’ school lives. When pupils feel comfortably and appropriately dressed it boosts self esteem.
“This in turn boosts mental health, which means pupils will be happier and more productive in schools. This leaders to better exam results which can lead pupils to better jobs.”