Michael Jay was born 19 June 1946, the son of Alan David Hastings Jay, DSO, DSC, RN and of Vera Frances Effa Vickery, MBE. He was educated at Winchester College, then Magdalen College, University of Oxford (becoming an Honorary Fellow in 2004), and took an MSc at the School of Oriental and African Studies, London University, in 1969. In 1975 he married Sylvia Mylroie.

Jay began his career at the Ministry of Overseas Development, 1969-73, and was a member of the UK Delegation to the International Monetary Fund and the International Bank for Reconstruction and Development, Washington [United States], 1973-75. He then returned to the Ministry of Overseas Development, 1976-78, before becoming First Secretary (Aid), New Delhi [India], 1978-81. Jay then joined the Foreign and Commonwealth Office in 1981, and his diplomatic career included the following posts: planning staff, 1981-82; Private Secretary to Permanent Under-Secretary [Antony Acland], 1982-85; Counsellor: Cabinet Office, 1985-87; Counsellor: (Financial and Commercial), Paris, 1987-90; Assistant Under-Secretary of State for EC Affairs, FCO, 1990-93; Deputy Under-Secretary of State (Director for EC and Economic Affairs), FCO, 1994-96; Ambassador to France, 1996-2001; Permanent Under-Secretary of State, FCO and Head of the Diplomatic Service, 2002-06; Prime Minister’s Personal Representative for G8 Summits, 2005-06.