Micheál Martin says it has been the honour of his life to serve as Taoiseach.
The Fianna Fáil leader handed his resignation to President Michael D Higgins this morning and confirmed the news to the Dáil.
TDs are now hearing nomination speeches for his replacement, Leo Varadkar.
Micheál Martin opened his Dáil speech with a tribute to the late Private Seán Rooney and his family, as he confirmed his resignation in the Dáil chamber this morning.
He also thanked his family and his local community in Cork for their support over the years.