He was born 31 January 1966 in New York city to Burmese parents and is the grandson of former UN Secretary-General U Thant. He was educated at Harvard, the Paul H. Nitze School of Advanced International Studies and the University of Cambridge. He received his PhD in history from Cambridge University in 1996.
Following the 1988 pro-democracy uprising in Burma, he spent a year on the Burmese-Thai border mainly assisting Burmese refugees and asylum seekers. He then spent two years in Washington D.C., in part working on Burma issues for Human Rights Watch and the US Committee for Refugees.
Thant Myint-U has served in three UN peacekeeping operations. He first worked with the UN from 1992-3, as a Human Rights Officer in the UN Transitional Authority for Cambodia in Phnom Penh. In 1994 he was the spokesman for the UN Protection Force in the former Yugoslavia, based in Sarajevo, and in 1996 was a Political Officer in the Office of the UN's Special Representative for Bosnia and Herzegovina.
From 1995-1999 he was a Fellow of Trinity College, Cambridge, where he taught and researched Asian and British colonial history. In 1999 he left Trinity College to become the Executive Officer of the Stockholm-based International Institute for Democracy and Electoral Assistance.
In 2000 he joined the UN Secretariat in New York From 2000-2002 he was a policy analyst in the Office for the Coordination of Humanitarian Affairs and then transferred to the United Nations Department of Political Affairs, becoming in 2004 head of the Policy Planning Unit in that department. During this time he was also a member of the secretariat of the Secretary-General's Panel on Threats, Challenges and Change (High Level Threat Panel) which produced "A More Secure World: Our Shared Responsibility". In late 2005 and early 2006 he was briefly a Senior Officer in the Executive Office of the Secretary-General working on UN reform issues.
He is the author of three books including The Making of Modern Burma (Cambridge University Press 2000) and The River of Lost Footsteps (Farrar, Straus and Giroux 2006). He has also written for The New York Times, The Washington Post, the International Herald Tribune, The London Review of Books, the New Statesman, the Far Eastern Economic Review, Time Magazine and The Times Literary Supplement.
He is currently a Visiting Senior Fellow at the International Peace Academy and a Research Associate of the Cambridge Centre for History and Economics.