Flappers were a subculture of young Western women in the 1920s who wore short skirts (knee height was considered short during that period), bobbed their hair, listened to jazz, and flaunted their disdain for what was then considered acceptable behavior. Flappers were seen as brash for wearing excessive makeup, drinking alcohol, smoking cigarettes in public, driving automobiles, treating sex in a casual manner, and otherwise flouting social and sexual norms. As automobiles became available, flappers gained freedom of movement and privacy.

Flappers are icons of the Roaring Twenties, the social, political turbulence, and increased transatlantic cultural exchange that followed the end of World War I, as well as the export of American jazz culture to Europe. There was a reaction to this counterculture from more conservative people, who belonged mostly to older generations. They claimed that the flappers' dresses were 'near nakedness', and that flappers were 'flippant', 'reckless', and unintelligent.

While primarily associated with the United States, the "modern girl" archetype was a worldwide phenomenon that had other names depending on the country, such as joven moderna in Argentina or garçonne in France, although the American term "flapper" was the most widespread internationally.