John, Lord Alderdice, (born 1955) is a British politician who comes from Northern Ireland.

He was leader of the Alliance Party of Northern Ireland from 1987 to 1998, Speaker of the Northern Ireland Assembly from 1998 to 2004, and then one of four members of the international Independent Monitoring Commission (IMC) appointed by the British and Irish Governments to oversee the standing down of the terrorist groups and normalization of security. Since 1996 he has sat in the House of Lords as a Liberal Democrat and was elected President of Liberal International in 2005, serving until Liberal International’s Cairo congress in 2009. Lord Alderdice is a Presidente D’Honneur of Liberal International and the only President or former President to have received LI’s highest honour – the Liberal International Prize for Freedom in 2015. He continues to serve on the Bureau of LI.

John Alderdice was educated at Ballymena Academy and the Queen’s University of Belfast (QUB). He worked as a consultant psychiatrist in psychotherapy in private practice and in the NHS from 1988 until he retired from psychiatric practice in 2010. He lectured at Queen’s University Belfast in the Faculty of Medicine between 1991 and 1999 and is currently a Professor of Practice at the Senator George J Mitchell Institute for Global Peace, Security and Justice at Queen’s University, and at the Global Humanity for Peace Institute of the University of Wales Trinity St David. He is a Senior Research Fellow at Harris Manchester College, Oxford, an Honorary Fellow of Pembroke College, Oxford, and a Visiting Fellow at Jesus College, Cambridge.

The Alliance Party of Northern Ireland was formed in 1970 as an alternative to sectarian politics. John Alderdice was on the Executive Committee of the party between 1984 and 1998, chaired the Policy Committee from 1985 to 1987, was elected the party vice-chair in 1987 and then elected Party Leader after the 1987 UK General Election in which he contested Belfast East for the party. He received 32.1% of the vote, the highest percentage achieved by Alliance in an individual seat in a Westminster election until Naomi Long’s historic victory for the party in Belfast East in the 2010 general election.

In Alliance’s 1988 document, “Governing with Consent”, Alderdice had called for a devolved power-sharing government based on a cross-community coalition with protections for minority rights and north-south cooperation on the island of Ireland. These Alliance policies were reflected ten years later in the 1998 Belfast/Good Friday Agreement which he and the other Northern Ireland parties negotiated with the British and Irish governments, and which brought an end the terrorist campaigns that had plagued Ireland for generations. He stepped down as Alliance Leader after the 1998 Assembly election and became the first Speaker of the new Northern Ireland Assembly, serving until 2004 when he was appointed to the IMC. As a member of the UK House of Lords he continues to make interventions on Northern Ireland and is a member of the House Select Committee on International Relations and Defence.

Lord Alderdice writes, lectures and consults globally on political violence, fundamentalism, the wellbeing and contributions of indigenous peoples, and challenges to liberalism.