Stepdancing as a modern form is descended directly from sean nós ("old style") stepdancing. There are in fact many other forms of stepdancing in Ireland (such as the Connemara style stepdancing), but the style most familiar is the Munster, or southern, form, which has been formalized by An Coimisiún le Rincí Gaelacha, which first met in 1930. An Coimisiún was formed from a directorate of the Gaelic League during the so-called Modern Revival.

Irish stepdance has very precise rules about what one may and may not do and when, but within these rules there is almost infinite room for variety and innovation. Thus, Irish stepdancing is a vibrant and constantly evolving art form.

The English landlords frowned on dancing (and indeed, all forms of Irish culture) as subversive, but the tradition never truly disappeared. In the nineteenth century, the Irish diaspora spread Irish dance all over the world, especially to North America and Australia.

One explanation for the unique habit of keeping the hands and upper body stiff relates to the stage. In order to get a hard surface to dance on, people would often unhinge doors and lay them on the ground. Since this was clearly a very small "stage", there was no room for the movement of the arms. But perhaps the most likely explanation is a practical one. The solo dances are characterized by quick, intricate movements of the feet. Reportedly, as in "sean nós" (old style) dancing, the arms were kept relaxed or with fists on the hips before the late 1890's.

Sometime in that decade or the one following, a dance master had his students compete with arms held firmly down to their sides, hands in fists, in order to call more attention to the intricacy of the steps. The adjudicator approved by placing the students well. Other teachers and dancers quickly followed the new trend. Movement of the arms is sometimes incorporated into modern Irish stepdance, although this is generally seen as a hybrid and non-traditional addition.