Born on 13 August 1876, at Kilkeeven, near Castlerea, County Roscommon, the elder son of Edward Flanagan, a smallholding farmer and Mary Crawley. O'Flanagan's parents were bi-lingual native Irish speakers. They were engaged in Fenian politics, and members of the Land League. He received his primary education at Cloonboniffe National School before traveling to Sligo where he attended secondary school at Summerhill College. Michael matriculated in 1894, and continued his education at St Patrick's College, Maynooth where he was ordained for the Diocese of Elphin in 1900. After joining the priesthood he returned to Summerhill College where he was employed as a teacher until 1904. Flanagan was a brilliant student, who grew very tall in stature: he won prizes in Theology, Scripture, canon Law, Irish language, education, and natural science. Later in life as a teacher, more than a catholic priest he filed patented inventions for protective goggles, and house insulation products. He was ordained by the Bishop of Elphin on 15 August 1900. That same year he was appointed Professor of Irish at Summerhill. He would organize the annual Sligo Fheis - a gaelic festival, that reflected his fenian pretensions. His success here made him a highly-sought after by Sinn Fein party organizsers.
In 1904 he was invited to speak on a tour of USA for Bishop Clancy of Elphin and Sir Horace Plunket, the radical party organizer. He was sent to find investment for agricultural and industrial projects in the west of Ireland. His brilliance as a motivating orator assembled support for a green agenda, emphasising co-operation. In August 1910 he was elected by the Gaelic League Executive and returned with Fionan MacColuim. In 1912, after several years of annoying the British authorities and the Catholic hierarchy he was appointed to a Curacy in the town of Roscommon, friendly to the ideas of Sinn Féin. O'Flanagan became involved with Irish language revival while teaching. He was a skilled orator and started agitating for radical social and political change. In October 1912, Bishop Clancy died, and was replaced by a far less sympathetic incumbent. Bishop Bernard Coyne was a moderate, conservative figure who accused O'Flanagan of intemperate modernism. The priest began to move away from the vocational calling towards a political life.
The following year he was elected to the Standing Committee of the Gaelic League for two years. In the year that war broke out with Germany he was sent again to preach at Rome on an independent Ireland. On 1 August 1914, He was moved by the diocese to Cliffoney and Grange parish. There he called for land distribution to his parishioners, condemned the export of food from the area, and demanded a continuation of peat bog cutting. He wrote profusely, attacking in the newspapers, what he felt was Irishmen's reluctant to perceive what oppression had been in Ireland for centuries was then being felt in Belgium.
In 1915 Father O'Flanagan was transferred to Cootehall, near Boyle, County Roscommon and was sanctioned by his Bishop when accused of making a speech disloyal to the crown: he had spoken at the funeral of Father Jeremiah O'Donovan Rossa, and old comrade in arms. The seperatist-style rhetoric was used to speak against war taxes imposed by London.
He also offended nationalists in a letter to the Freeman's Journal in June 1916 when he supported Lloyd George's proposal that the twenty-six counties should have immediate home rule. he moved towards support for partition arguing that the reality of Ulster separatism meant that to rid Ireland of the British was more important. The war agitation led to election as Vice-President of Sinn Féin in October 1917 for three years. He made the post his own, proving a highly effective party manager. In May 1918, Sinn Féin were rounded up, but clerical exemption, spared O'Flanagan arrest and imprisonment. During the General Election he toured the country talking to candidates and crowds. He was censored by the bishop but stated that it was essential to Ireland that East Cavan elect a Sinn Féin candidate. Nonetheless he became more queasy about the increasing level of violence deployed by the IRA, and shrank from appearing with them in public.
Vice-President of Sinn Féin, O'Flanagan was chosen to recite the invocation at the first meeting of the newly proclaimed Dáil Éireann in January 1919. He was appointed as the Chaplain to the dual parliament on its formation. On the Sinn Féin Land Executive he was responsible for the agitation of propaganda and agriculture in County Roscommon. And by December 1920 was promoted as Acting-President of the party.
In late January 1921, during the Irish War of Independence, O'Flanagan met informally in London with Sir Edward Carson and Judge James O'Connor to discuss a peaceful solution to the conflict, but without success. Nearly a year later the Anglo-Irish Treaty was ratified by both sides. He also had talks with Prime Minister Lloyd George.They discussed the dominion status of a free state, to which O'Flanagan was happy to agree. His critics accused him of waving a "white flag", but O'Flanagan was a convinced Anti-Treatyite, and a friend of Joseph J. O'Kelly, and as such was forced to leave Ireland, in fear of his life. The Crown issued a reward for his capture, arrest and prosecution. He was forced to flee to USA until April 1925. In November 1921, he arrived in America. In 1923 he went to Australia, and in a famous encounter met the friend of Irish nationalism Cardinal Daniel Mannix, Archbishop of Sydney. The Crown hunted O'Flanagan in Australia, eventually driving him out of the country by deportation.
In 1927 he was suspended from clerical duties because of his nationalist activities. Bishop Coyne finally died in July 1926, which lifted the ban on his ministry. However he was never again promoted by the Vatican and Catholic church. He did at this time flirt with Communism, and the marxist aesthetic, expressing brotherhood with James Larkin, union leader. But O'Flanagan never became a member of the left-wing groups, choosing to keep his distance from labourism.
In March 1926, Sinn Féin held its Ard Fheis. Flanagan led the section from which Éamon de Valera broke away. The conference instructed a joint committee of representatives from De Valera's faction and that of O'Flanagan to arrange a basis for co-operation. The Ard Fheis issued a statement declaring "the division within our ranks is a division of Republicans."  The split concerned entry to Dáil Éireann in 1926. De Valera took the great majority of Sinn Féin support with him when he founded Fianna Fáil but O'Flanagan maintained his radical stance on social issues in the republican journal An Phoblacht. He opposed De Valera's attempts to modernise the Oath of Allegiance, so that republicans could enter the revolutionary Dail Eireann. He split from 'Dev' on the founding of the Fianna Fail, deciding to remain ultimately with Sinn Féin.
O'Flanagan pursued theoretical and liteary interests in publishing 1927-8 several edition of the Ordnance Survey books. He was commissioned by the government to write a history of the irish language for schools, five of which were published, and five were not. He was elected president of Sinn Féin from October 1933 to 1935, when he was expelled from the party for taking a state job on the Placenames Commission and participating in a Radio Éireann programme.
Bernard O'Higgins, a critic and Mary MacSwiney were both complainants about his Presdency of Sinn Féin, and resigned in protest. In 1936 he took part in a re-enactment of the Dail re-opening, interpreting it as a triumph, and he was expelled by the purists in his party; later re-joining. He sympathised with Italian fascists when they invaded Abyssinia because they were enemies of Britain. He was one of the few Catholic priests to defend the Spanish Republic during the Spanish Civil War.
On 3 April 1939, he was restored to his faculties by a new Bishop of Elphin. In retirement he moved to Dublin, and acted as a Chaplain in the new Eire, of two convents and a hospital. He died in a Dublin nursing home of stomach cancer on 7 August 1942. A friend to the poor, and enemy to injustrice and patronage. He was also a doctrinaire social Catholic. But his character was said to be arrogant and egotistical. His maverick political conduct, both isolated and frustrated his friends. The British forces nearly captured him on several occasions, but his refusal to get involved in the fighting, gave him a loophole to escape certain death.
O'Flanagan remains today one of the heroes of Sinn Féin Party both in Northern Ireland and in Republic.
-  O'Flanagan at Sligo Heritage. Retrieved 16 October 2007.
- The Spark
- The Leader, 1916.
- Patrick Murray, ‘O'Flanagan, Michael (1876–1942)’, Oxford Dictionary of National Biography, Oxford University Press, 2004
- No. 129 UCDA P150/1902 http://www.difp.ie/docs/volume/1/1921/129.htm
- Dictionary of Irish National Biography
- The Times, Irish Republican Split. Search For Basis Of Cooperation 13 March 1926
- Patrick Murray, "O'Flanagan, Michael (1876–1942)", Oxford Dictionary of National Biography, Oxford University Press, 2004
- Cronin, Seán (1981). Irish nationalism: a history of its roots and ideology. Continuum. p. 279. ISBN 9780826400628.
- Dictionary of Irish National Biography
|Party political offices|
Jennie Wyse Power (1911–)
|Vice-President of Sinn Féin
with Arthur Griffith (1917–1922)
P. J. Ruttledge
|Leader of Sinn Féin
Cathal Ó Murchadha