Frank Aiken (13 February 1896 - 18 May 1983), was an Irish Fianna Fáil politician, revolutionary, longtime foreign minister and Tánaiste of the Republic of Ireland (1959-1969).

Frank Aiken was born on 13 February 1896 in County Armagh. He was educated by the Christian Brothers in Newry and in 1914 he joined the Irish Volunteers. In 1921 he became commandant of one of the IRA's Northern Divisions. In this role he led many attacks against British forces. When the Irish Civil War broke out in 1922 Aiken tried to remain neutral for as long as possible. In April 1923 he became Chief of Staff of the IRA. On 24 May he called a ceasefire.

Aiken was first elected to Dáil Éireann in 1923. In 1926 he became a founder-member of Fianna Fáil and was appointed MInister for Defence in the first Fianna Fáil government in 1932. During World War 2 Aiken served as Minister forCo-ordination of Defensive Measures. In the government which followed The Emergency, Aiken was appointed Minister for Finance.

Between 1951 and 1969 (except from 1954 to 1957 when Fianna Fáil were in opposition) Aiken served as Minister for External Affairs. At the United Nations he won the respect and admiration of smaller nations for taking an independent stance, on behalf of Ireland, on a range of controversial issues. In 1959 Aiken was appointed Tánaiste underSean Lemass. He was also appointed Tánaiste under Jack Lynch in 1966. He introduced the so-called 'Aiken Plan' to combine disarmament and peace in the Middle East. He received the honour to sign as first minister the Nuclear Non-Proliferation Treaty in 1968 in Moscow. Aiken retired from Ministerial office in 1969 and from politics completely in 1973. Aiken received many award and accolades from Irish universities and was a life-long promoter of the Irish language.

Frank Aiken died on 18 May 1983 in Dublin.