Patrick McCartan (13 March 1878 – 28 March 1963) was an Irish republican and politician. He was born in Eskerbuoy, near Carrickmore, County Tyrone, one of five children, to Bernard McCartan, a farmer, and the former Bridget Rafferty. He emigrated to the USA as a young man and became a member of Clan na Gael in Philadelphia, Pennsylvania and edited the journal Irish Freedom. He returned to Ireland some years later and qualified as a doctor. He also continued working with nationalist politics and worked closely with Bulmer Hobson and Denis McCullough with the Dungannon Clubs and the Irish Republican Brotherhood.
McCartan was to take part in the 1916 Easter Rising with the Tyrone volunteers but did not, owing to Eoin MacNeill's countermanding order. He was arrested after the Rising and interned in an open prison in England. In 1917 he took "French leave" to return to Ireland and assist Sinn Féin in the by-elections being held throughout Ireland that year.
McCartan contested the by-election in South Armagh for Sinn Féin but lost out to the Irish Parliamentary Party candidate. He was later elected in a by-election in King's County Tullamore in 1918. He was re-elected in the 1918 general election, and at the meeting of the First Dáil was appointed Sinn Féin's representative in the USA where he would remain until 1921. While in the USA he renewed his acquaintance with his fellow Carrickmore native Joseph McGarrity. They persuaded Éamon de Valera to support the Philadelphia branch of Clan na Gael against the New York branch led by John Devoy and Judge Daniel Cohalan in their struggle to focus the resources of the Friends of Irish Freedom to Irish independence rather than domestic American politics. McCartan also assisted with the development of the American Association for the Recognition of the Irish Republic.