Records of members of the Oireachtas
Name Office Years
Seán Lemass Minister for Industry and Commerce 19 years , 2 months
Éamon de Valera Minister for External Affairs 15 years , 11 months
Frank Aiken Minister for External Affairs 15 years , 3 months
James Ryan Minister for Agriculture 14 years , 10 months
Thomas Derrig Minister for Education 14 years , 1 month
Gerald Boland Minister for Justice 11 years , 4 months
Oscar Traynor Minister for Defence 11 years , 4 months
Seán MacEntee Minister for Finance 10 years , 5 months
Longest-serving cabinet ministers ( in same office )
This is a list of records relating to the Oireachtas, the national parliament of Ireland, which consists of the President of Ireland, and two Houses, Dáil Éireann, a house of representatives whose members are known as Teachtaí Dála or TDs, and Seanad Éireann, a senate whose members are known as senators. The First Dáil consisted of the Sinn Féin MPs who were elected in the United Kingdom general election of 14 December 1918. They refused to attend the British House of Commons and instead assembled for the first time on 21 January 1919 in the Mansion House in Dublin as the revolutionary unicameral Dáil Éireann. 1,292 TDs have served in the Dáil between 1919 and 2018. The title Father of the Dáil is usually and unofficially conferred on the longest-serving member.