Irish stepdance is a style of performance dance with its roots in traditional Irish dance. It may be generally characterized by a stiff upper body and fast and precise movements of the feet, and can be performed solo or in groups. Aside from public dance performances, there are also stepdance competitions all over the world. These competitions are often called Feiseanna (singular Feis). In Irish dance culture, a Feis is a traditional Gaelic arts and culture festival. Contemporarily, costumes are sometimes considered important in Irish stepdance; costumes are typically designed to attract the judge's eye in competitions and the audience's eye in performance, with widely varying colors and patterns. In many cases, costumes are sold at high prices and can even be custom made. General appearance beside the costume is also equally important, with female dancers typically wearing curly wigs or curling their hair and male dancers often neatly styling their hair to a shape to their liking for competition or performance. Additionally, poodle socks are worn by female dancers while males wear plain black socks. Poodle socks are white socks that have distinctive ribbing, and can be embroidered with gems. This hyper-stylization originated in the Irish diaspora, while traditional costume was homemade or from the local dressmaker and embroidered with Celtic knots and designs.

Riverdance, an Irish step-dancing performance in the 1994 Eurovision Song Contest that later became a hugely successful theatrical production, greatly contributed to its popularity. Once Riverdance became a large production, it changed the way that Irish dance was performed and viewed. Now that entrepreneurs could capitalize on Irish culture, they were able to tweak it to the audience's liking. This meant adding a theatrical flair to the performance, including arm movements (as opposed to the previously rigid top half that dancers maintained) as well as sexualizing the dance and the costumes. To some, this was a betrayal of tradition, but to others, it was a way of expanding Irish culture and became widely accepted. Following after Riverdance was Lord of the Dance and many other theatrical productions based on Irish stepdance; Michael Flatley, an Irish stepdancer, became a well-known name within these shows.

Two types of shoes are typically worn in Irish stepdance: hard shoes, which make sounds similar to tap shoes; and soft shoes (also called Ghillies), which are similar to ballet slippers. There are different dances specific to each type of shoe, and different types of music with varying beats are played based on the dance, although soft and hard shoe dances all share basic moves and rhythms.

The dancing traditions of Ireland are likely to have grown in tandem with Irish traditional music. Its first roots may have been in Pre-Christian Ireland, but Irish dance was also partially influenced by dance forms on the Continent, especially the quadrille dances. Some of the earliest recorded references to Irish dance are to the Rinnce Fada or "long dance", towards the end of the 17th century, which was performed largely during social occasions. Traveling dancing masters taught all over Ireland beginning around the 1750s and continuing as late as the early 1900s.

By the late 19th century, at least three related styles of step dance had developed in Ireland. The style practised in Munster saw dancers on the balls of their feet, using intricate percussive techniques to create complex rhythm. On the other hand, a tradition developed in Ulster saw dancers instead using their heel to create a persistent drumming effect, and primarily performing in pairs. The Connemara style, later described as sean-nós dance, combined heel and ball movements with the swaying of the torso and vigorous movement of the arms.

The foundation of the Gaelic League in 1893, an Irish nationalist body formed with the purpose of preserving traditional Irish language and culture, radically altered the cultural status of step dance. Frank Hall has described this as the moment in which "step-Dancing in Ireland became 'Irish dancing'", and as therefore the most significant single event in the development of the dance form. Although informal competitions had long been held between towns and students of different dance masters, the first organised feis was held in 1897 by the League. The League began to codify and promote the form of step dance which was practiced in southern areas. This codification, practised from the early 1920s, greatly narrowed the range of traditional Irish dances acceptable in popular culture.

In 1927, the Gaelic League set up An Coimisiún Le Rincí Gaelacha (CLRG, the Irish Dancing Commission), a separate body dedicated to the organisation and standardisation of Irish dance. CLRG created certifications for dance teachers and began to hold examinations for adjudicators of feisanna.

In the 19th century, the Irish diaspora had spread Irish dance all over the world, especially to North America and Australia. However, schools and feiseanna were not established until the early 1900s: in America these tended to be created within Irish-American urban communities, notably in Chicago and Massachusetts. The first classes in stepdancing were held there by the Philadelphia-born John McNamara.