Adams who has led Sinn Féin since 1983, outlined his plans at the party’s Ard Fhéis (annual conference) in Dublin on Saturday evening in a speech billed as “historic and significant”.
Also warning that Brexit is the biggest threat to the Irish people in generations, he told delegates this would be his last conference as party leader.
He claimed: “Leadership means knowing when it is time to change. That time is now.”
A date will be agreed in 2018 to elect his successor, he added, claiming he had complete confidence both in the current leadership and future leaders. He also thanked those who had “welcomed me into their homes and communities and made me part of countless campaigns, elections and negotiations.”