Ruairí Ó Brádaigh was an Irish republican political and military leader. He was Chief of Staff of the Irish Republican Army (IRA) from 1958 to 1959 and again from 1960 to 1962, president of Sinn Féin from 1970 to 1983, and president of Republican Sinn Féin from 1987 to 2009.

Republican Sinn Féin or RSF is an Irish republican political party in Ireland. RSF claims to be heirs of the Sinn Féin party founded in 1905; the party took its present form in 1986 following a split in Sinn Féin. RSF members take seats when elected to local government in the Republic of Ireland, but do not recognise the validity of the Partition of Ireland. It subsequently does not recognise the legitimacy of the parliaments of Northern Ireland (Stormont) or the Republic of Ireland, so the party does not register itself with them.