The Corsican mafia is a set of criminal groups which are part of the French Mob, originating from Corsica. The Corsican mafia is an influential organized crime structure, operating in France, Russia, and many African and Latin American countries. The most important groups of the Corsican mafia include the Unione Corse and the Brise de Mer gang.

The pre-war crime kings of Marseille, Paul Carbone and François Spirito, sided with Vichy and the Germans. During World War II, the Corsican gang led by the Guerini brothers (Antoine and Barthélémy, nicknamed "Mémé") sided with the Gaullist part of the French Resistance.

In 1947, Marseille was the main trading port of the French colonial empire and it had a communist mayor, Jean Christofol, who was backed by the trade unions, popular among longshoremen, transportation workers, and dockworkers. In the coming Cold War (1947–53), both the center-left French government and the US tried to fight communist influence in Marseille while occasionally employing illegal means to further their goal: the Guerini gang was employed to disrupt union and electoral gatherings, back strikebreakers and support US-funded non-communist trade unions.

From the 1950s to the 1960s, the Guerini brothers were exempt from prosecution in Marseille. The Guerini brothers trafficked opium derivatives illegally imported from French Indochina using the services of the Messageries Maritimes, a French merchant shipping company.

From the 1960s to the early 1970s the major Corsican gangs called Union Corse by American authorities organized the French Connection, a heroin trade between France and the United States.

The end of the French Connection caused the disbandment of Corsican clans involved in the heroin trade. However, the evolution of the Corsican Mafia has continued in several illegal activities (hold-ups, racketeering, casinos, illegal slot machines, various drug dealing and prostitution).

From the 1980s to the end of the 2000s, the Corsican mafia was split into two major groups; the Brise de Mer, based in Northern Corsica, and the Colonna clan (also named "Jean Jé Colonna's family"), based in Southern Corsica. A violent internal conflict troubled the Corsican mafia in 2007, resulting in around 102 murders on the island of Corsica. This conflict caused the fall of these two groups and the rise of new Corsican gangs.^[1]

Today, the Corsican mafia consists of multiple families, allies, and rivals. Known groups in the Corsican mafia are the Venzolasca gang (nickname in reference to the village of Venzolasca, in northern Corsica, which are from key members of the gang), considered the Brise de Mer successors. The "Petit Bar" gang (also called the "Tiny Bar"), the Valinco mobsters, and the Corsican mob of Marseille are also active.