Seán Harrington (1900–1976) was an Irish republican paramilitary who later became a prominent member of the Society of Friends.

Biography Born in Dublin,Muriel Seltman, What's Left? What's Right?, p.17 Harrington joined the Irish Republican Army (IRA),T. J. Barrington, Discovering Kerry: Its History, Heritage & Topography, p.128 and fought in the Irish War of Independence. He opposed the Anglo-Irish Treaty and remained with the anti-Treaty IRA through the Irish Civil War.Muriel Seltman, What's Left? What's Right?, p.24-25 On release, Harrington relocated to Dublin, where he found work as the caretaker at the Court Laundry. This was a difficult role, as local levels of crime were high. In December, he was tied to his bed and beaten, taking three months to recover; he apprehended an armed robber in April 1946."House-breaking in Dublin", Irish News, 1 April 1946

He broke his links with the paramilitary movement and also left the Catholic church, joining a group of Quakers; this group attracted some opposition, and Harrington lost the hearing in one ear after being attacked by a group of young Catholic extremists.

By the late 1960s, Harrington had left Ireland and moved to Tring in Hertfordshire.

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