Mary Patricia McAleese ( MAK-ə-LEESS; Irish: Máire Pádraigín Mhic Ghiolla Íosa; née Leneghan; born 27 June 1951) is an Irish activist lawyer and former politician who served as the eighth president of Ireland from November 1997 to November 2011. She is an academic and author and holds a licentiate and doctorate in Canon law. McAleese was first elected as president in 1997, having received the nomination of Fianna Fáil. She succeeded Mary Robinson, making her the second female president of Ireland, and the first woman in the world to succeed another woman as president. She nominated herself for re-election in 2004 and was returned unopposed for a second term. McAleese is the first president of Ireland to have come from either Northern Ireland or Ulster.

McAleese graduated in law from Queen's University Belfast. In 1975, she was appointed Professor of Criminal Law, Criminology and Penology at Trinity College Dublin, and in 1987 she returned to her alma mater, Queen's, to become director of the Institute of Professional Legal Studies. In 1994, she became the first female pro-vice-chancellor of Queen's University. She worked as a barrister and as a journalist with RTÉ. She is an Honorary Fellow of St Edmund's College, Cambridge.

McAleese used her time in office to address issues concerning justice, social equality, social inclusion, anti-sectarianism and reconciliation. She described her presidency's theme as "Building Bridges". This bridge-building materialised in her attempts to reach out to the unionist community in Northern Ireland. These steps included celebrating the Twelfth of July at Áras an Uachtaráin and taking communion in a Church of Ireland cathedral in Dublin, for which she incurred some criticism from some of the Irish Catholic hierarchy. Though a Catholic, McAleese holds liberal views on homosexuality and women priests. She is a member of the Council of Women World Leaders and was ranked the 64th most powerful woman in the world by Forbes. In spite of some minor controversies, McAleese remained popular and her presidency is regarded as successful.