Black Brigades (Italian: Brigate Nere) were 40 fascist paramilitary groups operating in Italian Social Republic (in northern Italy), during the final years of World War II, and after the signing of the Italian Armistice in 1943. They were officially known as the Guardia Nazionale Repubblicana (GNR).

Benito Mussolini had been arrested after the Grand Fascist Council, with the support of King Vittorio Emmanuele III, overthrew him and began negotiations with the Allies for Italy's withdrawal from the war. Mussolini was rescued by German paratroopers and installed as the President of the Italian Social Republic, a puppet regime nominally administering the German-occupied northern Italy.

As the Milizia Volontaria per la Sicurezza Nazionale (MVSN, also known as "Black Shirts") was disbanded by the terms of the armistice, the Guardia Nazionale Repubblicana was formed on 24 November 1943 out of hard-core former MVSN, ex-carabinieri, ex-army and others still loyal to the fascist cause.

The Black Brigades were formed out of the more fanatical members. They not only fought the Allies, and Italian partisans, but also fought against and murdered their political opponents. Many were killed in the fighting.