Gadfly

Gadfly most commonly refers to:
 * Horse fly or botfly
 * Gadfly (philosophy and social science), a person who upsets the status quo

Gadfly may also refer to:

Entertainment

 * The Gadfly, an 1897 novel by Ethel Lilian Voynich
 * The Gadfly (play), an 1898 play by George Bernard Shaw
 * The Gadfly (1928 film), a Soviet film by Kote Marjanishvili
 * The Gadfly (1955 film), a Soviet film by Aleksandr Fajntsimmer
 * The Gadfly Suite, a musical suite by Dmitri Shostakovich for the 1955 film
 * The Gadfly (1980 film), a Soviet film by Nikolai Mashchenko
 * The Gadfly (opera), a 1958 Russian opera by Antonio Spadavecchia
 * Gadfly Online, an online and print magazine
 * The Gadfly (Adelaide), a 1906–1909 Australian literary magazine produced by C. J. Dennis
 * The Gadfly (album), a 2003 album by LPG
 * The Gadfly, a fictional play in the novels of Geoffrey Trease, see The Hills of Varna

Other uses

 * Gadfly (database), a relational database management system
 * Gadfly (mythology), the insect as sent by Hera to torment Io in Greek mythology
 * Gadfly, the NATO reporting name for a Russian 9K37 Buk surface-to-air missile system
 * Education Gadfly, the weekly e-bulletin of the Thomas B. Fordham Institute
 * Autism's Gadfly, a blog maintained by Jonathan Mitchell (writer)