John Guy was born in Australia in 1949 and came to England in 1952, growing up in Watford and Lancashire.
He studied history at Clare College, Cambridge, and became a lecturer on Early Modern British History and Renaissance Political Thought, in Britain and the United States. He has held academic positions throughout his career and is still a Fellow in History at Clare College, University of Cambridge, and an Honorary Professor at the University of St. Andrews, Scotland.
He is the author of many history books, including the popular textbook, Tudor England (1988), and My Heart is My Own: The Life of Mary Queen of Scots (2004), winner of the 2004 Whitbread Biography Award and shortlisted for the 2004 Biography/Autobiography of the Year Award in the US. Other books include Thomas More (2000); The Tudors: A Very Short Introduction (2000); A Daughter's Love (2008), on the daughter of Sir Thomas More; Thomas Becket: Warrior, Priest, Rebel, Victim (2012); The Children of Henry VIII (2013); and a book in the Penguin Monarchs series: Henry VIII (2014). Elizabeth: The Forgotten Years (2016) was shortlisted for the Costa Book Award for Best Biography.
John Guy appears regularly on BBC Radio and has presented five documentaries for BBC2 television, including the Timewatch film, 'The King's Servant' and the four-part 'Renaissance Secrets'. He also writes reviews for various newspapers and magazines, including the Sunday Times, The Guardian and The Economist.