Joseph McGrath (1887 – 1 March 1966) was an Irish politician. He was a Sinn Féin and later a Cumann na nGaedhael Teachta Dála for various constituencies in Dublin and County Mayo and developed widespread business interests.
McGrath was born in Dublin in 1887. He became involved in Irish nationalism and soon joined the Irish Republican Brotherhood. He fought in Marrowbone Lane in the 1916 Easter Rising. McGrath was arrested after the rising, and jailed in Wormwood Scrubs and Brixton prisons in England.
In the 1918 general election, he was elected Sinn Féin TD for the St James division of Dublin and later went on to become a member of the First Dáil. He was also a member of the Irish Republican Army, the guerrilla army of the Irish Republic, and successfully organized many bank robberies during the Irish war of Independence (1919–1921), where a small percentage of the proceeds was retained as a reward by him and his fellow-soldiers.
In October 1921, McGrath travelled with the Irish Treaty Delegation to London as one of Michael Collins' personal staff.
In the Irish Civil War of 1922-1923, he took the pro-treaty side and was made Director of Intelligence, replacing Liam Tobin. He was later put in charge of the police Intelligence service of the new Irish state, the Criminal Investigation Department or CID. It was accused of the torture and killing of a number of republican (anti-treaty) prisoners during the civil war and was disbanded at the war's end, being unnecessary for a police force in peacetime. McGrath went on to serve as Minister for Labour in the Second Dáil and the Provisional Government of Ireland. He also served in the 1st and 2nd Executive Councils holding the Industry & Commerce portfolio.
McGrath resigned from office in April 1924 because of dissatisfaction with the government's attitude to certain army officers and as he said himself, "government by a clique and by the officialdom of the old regime." By this he meant that former IRA fighters were being overlooked and that the Republican goals of an all Ireland republic had been sidelined, a cause of the "army mutiny". McGrath and eight other TDs who had resigned from Cumann na nGaedhael then resigned their seats to contest by-elections, running as the National Party. However, Cumann na nGaedhael won seven of these and Sinn Féin won the other two.