Born in Upper Dominick Street, Dublin, and educated by the Christian Brothers, he was an apprentice printer and journalist. Travelling to South Africa because of recession in 1896, Griffith worked in gold mines and sided with the Boers. He returned to Ireland at the turn of the century and in 1900, founded Cumann na nGaedheal, a cultural and education association aimed at the reversal of anglicisation, while later he was active in the Gaelic League and IRB.
In 1904 Griffith wrote The Resurrection of Hungary: A Parallel For Ireland which promoted economic self-sufficiency and self-government. In 1906 he founded Sinn Fein with policies of national economic, cultural and political self-reliance. Griffith joined the Irish Volunteers in 1913 but was not appointed to the IRB executive lest the new organisation appear too closely associated with Sinn Féin. He discouraged Irishmen from fighting with the British army in the war, as a result of which Sinn Féin was banned in December 1914.
Sinn Féin and the writings of Griﬃth played an influential role in developing a spirit of national self reliance in the years before the Rising. The public proﬁle of Sinn Féin was such that on the outbreak of the insurrection the British government and public at large assumed that it was responsible. The Rising being generally referred to as ‘the Sinn Féin Rebellion’. While some members of Sinn Féin took part in an individual capacity, neither the organisation nor Griﬃth himself was involved in the Rising.
Griffith took no part in the 1916 Rising but was still imprisoned. Released in 1917, he became a Sinn Fein MP in 1918, and was Acting President of the Dail Government of 1919-20 while Eamon de Valera was in America.
Griffith led the Irish delegates as chief negotiator in the Treaty talks of late 1921 and became President of the Dail but in 1922 died from a brain hemorrhage.