The Italian Resistance (Italian: Resistenza italiana [reziˈstɛntsa itaˈljaːna]), or simply La Resistenza, consisted of all the Italian resistance groups who fought the occupying forces of Nazi Germany and the fascist collaborationists of the Italian Social Republic during the Second World War in Italy from 1943 to 1945. As a diverse anti-fascist and anti-Nazist movement and organisation, the Resistenza opposed Nazi Germany and its Fascist puppet state regime, the Italian Social Republic, which the Germans created following the Nazi German invasion and military occupation of Italy by the Wehrmacht and the Waffen-SS from 8 September 1943 until 25 April 1945.
General underground Italian opposition to the Fascist Italian government existed even before World War II, but open and armed resistance followed the German invasion of Italy on 8 September 1943: in Nazi-occupied Italy, the Italian Resistance fighters, known as the partigiani (partisans), fought a guerra di liberazione nazionale ('national liberation war') against the invading German forces; in this context, the anti-fascist partigiani of the Italian Resistance also simultaneously participated in the Italian Civil War, fighting against the Italian Fascists of the collaborationist Italian Social Republic.