The leader of Sinn Féin is the most senior politician within the Sinn Féin political party in Ireland. Since 13 November , the office has been held by Gerry Background · Presidents · Vice Presidents · Parliamentary party leaders. MICHELLE O'Neill is Sinn Fein's leader in Northern Ireland, which they dub “the North”. Here's all you need to know about the woman who. Sinn Féin leader Gerry Adams has accused the DUP of lacking a sense of urgency in talks aimed at restoring power-sharing in Northern Ireland.