St Brigid's National School in Greystones in Co Wicklow has decided to introduce a gender neutral school uniform policy following proposals from the students' council.
The Irish Times reported that the school will allow boys to wear skirts or girls to wear trousers from next September.
Chair of the Board of Management Tom Sherlock said the council approached the principal earlier this year with a well thought out case.
He told RTÉ's Morning Ireland that the board's initial reaction was "why didn't we think of it ourselves?"
Mr Sherlock added that we live in a modern era and the Catholic schools' ethos is one of respect and inclusivity.
It was, he said, a "no-brainer", although he added that he realised it was a somewhat radical step, so the board decided to consult the parents' association before going ahead with the plan.
He said the response from the association was equally positive.
Mr Sherlock said some consideration was given to gender neutral toilets.
However, he added it was not a huge change for the school because there are separate boys and girls' toilets at the back of the classroom.