Andrew McHallam was born in April 1957. After studying History at Queens’ College, University of Cambridge, he joined the John Lewis Partnership in 1979, mainly working in personnel. In 1989 he moved to the Institute of European Defence and Strategic Studies (IEDSS), initially as editor of the Institute’s publications, and from 1992 as Director, then from 1999-2001 worked as a senior policy officer for the Association of Chief Police Officers.

In 2001 McHallam then joined the Foreign and Commonwealth Office and his FCO career included: Aviation, Maritime and Energy Department, 2002-04; Counsellor, OECD Delegation in Paris [France], 2004-08; seconded as Deputy Chief Executive, International Financial Services London, c 2008-10; head of the UK Economy Team in the Prosperity Directorate, FCO, 2011-13; Head of the Stakeholder Communications and Engagement Team for the FCO's move during the refurbishment of the London offices in the Estate Reform project, 2013-16; running the Chevening Scholarship Programme with oversight of the Marshall Programme, 2016-18. Following McHallam's retirement from the FCO, he then served as a Cabinet Office Reviewer, 2018-24.