The Irish School Heads' Association (ISA) was founded in 1869 as an Association of Headmasters of Protestant Schools in Ireland. In 1968 the ISA opened its ranks to women and the Headmistresses of Protestant Schools joined their male colleagues.
Membership of ISA is open to all Protestant Head Teachers of recognised Post-Primary Schools in Ireland and the objects of the Association are to advance the interests of post-primary education in Ireland and to afford its members the advantage of mutual counsel and support.
Standing Committee and General meetings are largely concerned with the current affairs of Irish Education, dealing with the same matters as would appear on a JMB agenda but in the context of their implications for the small number of schools serving the Protestant community in particular, and often with reference to the fact that the vast majority of ISA schools have a boarding element.



