From 2004-2012 Mike Aaronson was a Visiting Fellow of Nuffield College, where he is now an Honorary Fellow. From 2006-2018 he was a member of, and from 2013-2018 he chaired, the Fellows’ Remuneration Review Committee.

From 1995-2005 Mike was Director General (chief executive) of Save the Children UK, and from 1988-1995 was the charity’s Overseas Director. He first joined Save the Children in 1969, spending two years as a relief worker in Nigeria after reading philosophy and psychology at St John’s College, Oxford. Between 1972 and 1988 he held various posts in the UK Diplomatic Service, serving in London, Paris, Lagos, and Rangoon.

Mike is a founder member, and from 2001-2008 was Chair of the Board, of the Centre for Humanitarian Dialogue, a Geneva-based private foundation working to improve the international response to conflict, in particular through independent mediation. From 2001-2007 he was a Governor of the Westminster Foundation for Democracy in London, a non-departmental public body working to strengthen democracy in Africa, the Middle East, and the countries of the former Soviet Union; he was Vice Chair from 2005-2007. He has been an occasional Senior Adviser to NATO, working on the political/military aspects of NATO transformation, and has also lectured at the UK Defence Academy on civil/military collaboration in conflict situations.

From 2007-2012 Mike was a Civil Service Commissioner, appointed by the Crown to maintain the principle of fair and open recruitment to the UK Civil Service. From 2006-2016 he was Chairman of Frimley Park Hospital NHS Foundation Trust (now Frimley Health NHS Foundation Trust). From 2006-2018 he was a non-executive director of Oxford Policy Management Limited, a development consultancy firm based in Oxford.

In September 2008 Mike was appointed an Honorary Visiting Professor in the Department of Politics at the University of Surrey. In May 2011 he became a Professorial Research Fellow and Executive Director of cii - the Centre for International Intervention, at Surrey. In October 2015 he reverted to being an Honorary Visiting Professor, but continues as Director Emeritus of cii.

From 2016-2019 Mike chaired the Strategic Advisory Group of the Global Challenges Research Fund (GCRF), which channels £1.5bn of UK aid funding to support research into international development.

In January 2000 Mike was made a CBE and in June 2006 he was made a Knight Bachelor for services to children. In July 2011 he was awarded an Honorary Doctorate by the University of Surrey.​​