Peadar Clancy (Irish: Peadar Mac Fhlannchadha; 9 November 1888 – 21 November 1920) was an Irish republican who served with the Irish Volunteers in the Four Courts garrison during the 1916 Easter Rising and was second-in-command of the Dublin Brigade of the Irish Republican Army (IRA) during the War of Independence. Along with Dick McKee and Conor Clune, he was shot dead by British guards while under detention in Dublin Castle on the eve of Sunday, 21 November 1920, a day known as Bloody Sunday that also saw the killing of a network of British spies by the Squad unit of the Irish Republican Army and the killing of 14 people in Croke Park by British forces.
Clancy was one of seven sons and six daughters born to James and Mary Clancy (née Keane), of Carrowreagh East, Cranny, County Clare in 1888. The Clancy home had been the meeting place for local Fenians since the 1860s. Though the Fenians had been instrumental in reawakening Irish culture through the Gaelic League, drama and the Gaelic Athletic Association, this form of "advanced nationalism" was not popular at this time. From a young age Clancy was a keen Gaelic Leaguer and was engrossed by national activities. Educated at the local national school, which was close to his family home, at sixteen he became apprenticed in the drapery business of Dan Moloney, in Kildysart. On completing his apprenticeship he went to Newcastle West, County Limerick, where he worked as an assistant in the drapery business of Michael O'Shaughnessy on Bridge Street. From there, he moved to Youghal, County Cork, where he lived at 6 North Main Street, from which address he wrote to his infant nephew in Chicago on 17 October 1912. In 1913 he went to work for Harkin's General Drapery, at 70A New Street in Dublin.