SPECTRE (Special Executive for Counterintelligence, Terrorism, Revenge and Extortion) is a fictional global criminal syndicate and terrorist organisation featured in the James Bond novels by Ian Fleming, the films based on those novels, and James Bond video games. Led by evil genius and supervillain Ernst Stavro Blofeld, the international organisation first formally appeared in the novel Thunderball (1961) and in the film Dr. No (1962). As a NGO, SPECTRE is not aligned to any nation or political ideology, enabling the later Bond books and Bond films to be regarded as somewhat apolitical though the former Gestapo members are a clear sign of Fleming's warning of the Nazi fascists surviving after the Second World War first detailed in the novel Moonraker (1954). SPECTRE began in the novels as a small group of criminals but became a vast international organisation with its own SPECTRE Island training base in the films, to replace the Soviet SMERSH.

Spectre or specter usually refers to a ghost or other apparition. It may also refer to an optical illusion called a Brocken spectre.