The miniskirt is a skirt with a hemline well above the knees (generally 20cm or more above knee level). Its existence is generally credited to the fashion designer Mary Quant, who was inspired by the Mini Cooper automobile, although the French designer André Courrèges is also often cited as its inventor, and there is disagreement on who invented it first. Some credit the Miniskirt to Helen Rose who made some miniskirts for actress Anne Francis in the 1956 Sci Fi movie, Forbidden Planet.

Recently, Marit Allen, a Vogue "Young Ideas" editor at the time, has stated that "John Bates, in particular, has always been completely unappreciated for his contribution to the innovation and creativity he brought to the London design scene." He bared the midriff, used transparent vinyl and, Marit Allen asserts, was responsible for "the raising of the hemline. It was John Bates, rather than Mary Quant or Courrèges, who was responsible for the miniskirt." Bates' costumes and accessories for Diana Rigg in The Avengers define "Mod style."

Mary Quant ran a popular clothes shop on Chelsea, London's Kings Road called Bazaar, from which she sold her own designs. In the late 1950s she began experimenting with shorter skirts, which resulted in the miniskirt in 1965—one of the defining fashions of the decade.

Owing to Quant's position in the heart of fashionable "Swinging London", the miniskirt was able to spread beyond a simple street fashion into a major international trend.

The miniskirt was further popularised by André Courrèges, who developed it separately and incorporated it into his Mod look, for spring/summer 1965. His miniskirts were less body-hugging, worn with the white "Courrèges boots" that became a trademark. By introducing the miniskirt into the haute couture of the fashion industry, Courrèges gave it a greater degree of respectability than might otherwise have been expected of a street fashion.

The miniskirt was followed up in the mid-1960s by the even shorter micro skirt, which covers not much more than the intimate parts with the underpants. It has often been derogatorily referred to as a belt. Subsequently, the fashion industry largely returned to longer skirts such as the midi and the maxi. However, miniskirts remain popular.

The 1980s saw the miniskirt's introduction to the office. Many women began to incorporate the miniskirt into their business attire. Today, it is common to see a woman wearing a miniskirt in the office.

Around the turn of the 21st century, the micro has been reworked as an even less substantial "beltskirt", which is more an evocation of the idea of a skirt than something that covers anything substantial. It may perhaps also provide rhythm for the hipline. Due to its revealing nature, the "beltskirt" is rarely worn in public. Miniskirts are also seen worn over trousers or jeans, or with strap-on trouser "leggings" that provide coverage of each leg from above the knee.