Patrick Joseph O'Byrne KM (August 1870 – 20 January 1944) was an Irish republican and Sinn Féin politician.
[2] He did not follow Éamon de Valera who split from Sinn Féin in 1926 to found the Fianna Fáil party to enter the Dáil.
[3] He was the son of was John O'Byrne of Corville, County Tipperary (who had originally been granted the title of Count by the Pope) and his mother was Eleanor von Hübner, the daughter of Austrian diplomat Count Joseph Alexander Hübner.
He was a direct descendant of Edward Byrne (c.1739–1804), a wealthy Dublin merchant and Chairman of the Catholic Convention which campaigned for Catholic rights, and his son John Dominick Byrne, who was a member of the United Irishmen.
[4] His brother-in-law was John Pius Boland, the Home Rule MP for South Kerry.