Liberation Day, also known as the Anniversary of Italy's Liberation, Anniversary of the Resistance, or simply 25 April, is a national holiday in Italy that commemorates the victory of the Italian resistance movement against Nazi Germany and the Italian Social Republic, puppet state of the Nazis and rump state of the fascists, culmination of the liberation of Italy from German occupation and of the Italian civil war in the latter phase of World War II. That is distinct from Republic Day, which takes place on 2 June and commemorates the 1946 Italian institutional referendum.

The Italian Social Republic, known prior to December 1943 as the National Republican State of Italy, but more popularly known as the Republic of Salò, was a Nazi-German puppet state with limited diplomatic recognition that was created during the latter part of World War II. It existed from the beginning of the German occupation of Italy in September 1943 until the surrender of German troops in Italy in May 1945. The German occupation triggered widespread national resistance against it and the Italian Social Republic, leading to the Italian Civil War.