Michael O'Flanagan (Irish: An tAthair MĂcheál Ă“ Flannagáin; 13 August 1876 – 7 August 1942) was a Roman Catholic priest, Irish language scholar, inventor and historian.
He was a popular, socialist Irish republican; "a vice-president of the Irish Agricultural Organisation Society, he was a proponent of land redistribution." He was Gaelic League envoy to the United States from 1910 to 1912, and he supported the striking dockers in Sligo in 1913.O'Flanagan was friends with many of the leaders of the 1916 Easter Rising and was vocal in his admiration for the sacrifice made by the men of Easter Week.
After five months as Republican Envoy to Australia he was deported in 1923.
O'Flanagan, James Larkin and Frank Ryan were considered the best open-air orators of the twentieth century.He was suspended from the priesthood for many years because of his political beliefs and attitudes.
In later years he edited the 1837 Ordnance Survey letters and prepared sets for institutions and universities; in the 1930s he worked on a series of County Histories, and ten volumes were published by the time of his death.
He died in 1942, was given a State Funeral, and is buried in the Republican Plot in Glasnevin Cemetery.