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.

Dáithí Ó Conaill was an Irish republican, a member of the IRA Army Council of the Provisional IRA, and vice-president of Sinn Féin and Republican Sinn Féin. He was also the first chief of staff of the Continuity IRA, from its founding in 1986 until his death in 1991. He is credited with introducing the car bomb to Northern Ireland.