The 1957 Irish general election was held on Tuesday, 5 March, over four weeks after the dissolution of the Dáil on 4 February. It was the longest election campaign in the history of the state, spanning 30 days. The newly elected members of the 16th Dáil assembled at Leinster House on 20 March when the new Taoiseach and government were appointed. The general election took place in 40 parliamentary constituencies throughout Ireland for 147 seats in the lower house of parliament, Dáil Éireann.