At the party's AGM this morning, Mary Lou McDonald will succeed Gerry Adams as the leader of Sinn Féin.
Mr. Adams has been leader of the party for 35 years, but announced that he will be stepping down last year.
Mary Lou has been a TD since 2011 and is the TD for the Dublin Central constituency.
She was originally a member of the Fianna Fáil party before joining Sinn Féin.
