Michael O'Leary (8 May 1936 – 11 May 2006) was an Irish politician and barrister. He was Minister for Labour and while leader of the Labour Party became Minister for Energy and Tánaiste. He later became a member of the Fine Gael party.
Born in Cork, the son of a publican, O'Leary was educated at Presentation College, University College Cork, Columbia University, New York and King's Inns. On returning to Ireland, he became involved in Labour politics and was employed as Education Officer for theIrish Transport and General Workers' Union (ITGWU). In this rôle he was instrumental in establishing the Universities Branch, affiliated to Dublin North-Central Constituency, bringing together Dublin University Fabian Society and University College Dublin Labour Party students.
O'Leary was first elected to Dáil Éireann as a Labour Party Teachta Dála (TD) for Dublin North–Central at the 1965 general election. His agent was Bob Mitchell, Chairman of Dublin University Fabian Society, who could claim credit in a dirty campaign for picking up transfers to squeeze out the Labour Party front-runner on the 11th Recount.
When first elected to the Dáil, O'Leary encouraged the Labour Party to take a more left-wing stance in its policies. He was initially strongly opposed to the idea of a coalition with Fine Gael but after the 1969 general election he believed that there was a need for a new approach. When the Labour Party and Fine Gael formed the National Coalition government following the 1973 general election he was appointed Minister for Labour.
In 1977, he was narrowly defeated by Frank Cluskey for the leadership of the party. Cluskey resigned as Labour Party leader when he lost his Dáil seat at the 1981 general election and O'Leary was elected unanimously to succeed him. In the 1979 European Parliament election O'Leary was elected to the European Parliament for the Dublin constituency.
In the short-lived Fine Gael–Labour Party government of 1981 to 1982, O'Leary became Tánaiste and Minister for Energy. Shortly after the government defeat at the February 1982 general election he resigned as leader of the Labour Party and joined Fine Gael, subsequently being elected a TD for that party in the Dublin South–West constituency at the November 1982 general election. He was kept out of cabinet office by his former Labour colleagues.
In 1985, O'Leary introduced a private member's bill on divorce which forced the government into holding the 1986 divorce referendum.
When the Progressive Democrats were formed in 1985 he considered joining.
He did not contest the 1987 general election and afterwards he moved back to Cork and practised as a barrister. He unsuccessfully contested the 1992 general election in Cork North–Central and received about 2% of the valid poll. He was elected as a Fine Gael member of Cork City Council at the 1991 local elections.
He was appointed a District Court judge in 1997 by the Fine Gael–Labour Party–Democratic Left coalition government.
O'Leary died in France in May 2006 following a drowning accident in a swimming pool. He was on holiday, having retired as a judge just days earlier.