In 19th-century Tasmania, the term flash mob was used to describe a subculture consisting of female prisoners, based on the term flash language for the jargon that these women used.

Flash mobs began as a form of performance art.

In art, performance art is a performance presented to an audience, traditionally interdisciplinary. Performance may be either scripted or unscripted, random or carefully orchestrated; spontaneous or otherwise carefully planned with or without audience participation.

The first documented use of the term flash mob as it is understood today was in 2003 in a blog entry posted in the aftermath of Wasik's event. The term was inspired by the earlier term smart mob.

A smart mob is a group that, contrary to the usual connotations of a mob, behaves intelligently or efficiently because of its exponentially increasing network links.

One of the first flash mobs was created in Manhattan in May 2003, by Bill Wasik, senior editor of Harper's Magazine. (...)

More than 130 people converged upon the ninth floor rug department of the store, gathering around an expensive rug. Anyone approached by a sales assistant was advised to say that the gatherers lived together in a warehouse on the outskirts of New York, that they were shopping for a "love rug", and that they made all their purchase decisions as a group. Subsequently, 200 people flooded the lobby and mezzanine of the Hyatt hotel in synchronized applause for about 15 seconds, and a shoe boutique in SoHo was invaded by participants pretending to be tourists on a bus trip.

Wasik claimed that he created flash mobs as a social experiment designed to poke fun at hipsters and to highlight the cultural atmosphere of conformity and of wanting to be an insider or part of "the next big thing"