A ballroom or ballhall is a large room inside a building, the primary purpose of which is holding large formal parties called balls. Traditionally, most balls were held in private residences; many mansions and palaces, especially historic mansions and palaces, contain one or more ballrooms. In other large houses, a large room such as the main drawing room, long gallery, or hall may double as a ballroom, but a good ballroom should have the right type of flooring, such as hardwood flooring or stone flooring .. For most styles of modern dance, a wooden sprung floor offers the best surface.

A ball is a formal dance event often characterised by a banquet followed by a social dancing. Ball dancing emerged from formal dances during the Middle Ages and carried on through different iterations throughout succeeding centuries, such as the 17th century Baroque dance and the 18th century cotillion. Several variations exists such as the masquerade and debutante ball as well as the more modern prom.