The executions during the Irish Civil War took place during the guerrilla phase of the Irish Civil War. This phase of the war was bitter, and both sides, the government forces of the Irish Free State and the anti-Treaty Irish Republican Army (IRA) insurgents, used executions and terror in what developed into a cycle of atrocities. From November 1922, the Free State government embarked on a policy of executing Republican prisoners in order to bring the war to an end. Many of those killed had previously been allies, and in some cases close friends, of those who ordered their deaths in the civil war. In addition, government troops summarily executed prisoners in the field on several occasions. The executions of prisoners left a lasting legacy of bitterness in Irish politics.

The National Army, sometimes unofficially referred to as the Free State army or the Regulars, was the army of the Irish Free State from January 1922 until October 1924. Its role in this period was defined by its service in the Irish Civil War, in defence of the institutions established by the Anglo-Irish Treaty. Michael Collins was the army's first commander-in-chief until his death in August 1922.