Stormont junior minister Martina Anderson is to become an MEP for Sinn Féin replacing Bairbre de Brún.
Martina Anderson was chosen at a convention in Derry to replace De Brún, who is standing down from the European Parliament because of health reasons.
Ms Anderson, 50, is a former IRA prisoner from Derry who was first elected to the Northern Ireland Assembly in 2007.
Martina Anderson was also one of the party's first representatives to sit on the Policing Board.
Ms Anderson played a key role with the power-sharing executive in Belfast to establish an inquiry into institutional child abuse.
