The Army Comrades Association (ACA), later named National Guard and better known by their nickname The Blueshirts (Irish: Lucht na Léine Gorma), were an Irish political organisation set up by General Eoin O'Duffy in 1932. O'Duffy was a guerrilla leader in the Irish Republician Army (IRA) during the Irish War of Independence, an Irish Army general during the Civil War that followed, and the Irish police Commissioner for the resultant Irish Free State from 1922 to 1933.

It has been regarded as Ireland's equivalent of Adolf Hitler's Brownshirts and Benito Mussolini's Blackshirts which were all members of the European fascist movement. Indeed, in December 1934, O'Duffy attended an International Fascist Conference in Montreux, Switzerland at which there were representatives from 13 other countries - Austria, Belgium, Denmark, France, Greece, The Netherlands, Italy, Lithuania, Norway, Portugal, Romania, Spain and Switzerland. The argument that the Blueshirts were fascists is generally based on their own adherence to Radical Right-Wing ideology (with a particular admiration for Mussolini) as well as their paramilitary-style uniforms, use of the Roman salute (members shouted "Hail O'Duffy!" at rallies ), militant Catholicism and anti-communism and a belief in corporatism.

Its leaders argued that they were simply defending democracy, citing the actions of the IRA, which had attempted to break up meetings of the opposition Cumann na nGaedheal party whom they regarded as 'traitors' for accepting the Anglo-Irish Treaty.

However, Anti-Blueshirt organizations such as the Anti-Treaty Fianna Fáil Party, the IRA, and the Communist Party of Ireland cited the example of other fascist movements coming to power where any democratic process was extinguished and how the Blueshirts clearly attempted to emulate this by their 'March on Dublin'.