Biographies:
* Diana: Her True Story - In Her Own Words (2000): This book, published in collaboration with the late Diana's former butler Paul Burrell, offers insights into Diana's life and thoughts, based on her personal letters and diaries.
* William and Harry: The Inside Story of a Family in Crisis (1999): A controversial book exploring the fallout of the divorce between Prince Charles and Diana and its impact on their sons, Prince William and Prince Harry.
* Prince Charles: The Misunderstood Man (2007): This book portrays Charles's life and work in a more favorable light, seeking to challenge the perception of him as an unpopular figure.
* The Death of Diana: The Inside Story (1998): This book delves into the investigation surrounding Diana's tragic death in a car crash in Paris, highlighting the conspiracy theories surrounding the incident.
Historical Non-fiction:
* Blenheim: Palace of Dreams (2016): A detailed account of the history of Blenheim Palace, the ancestral home of the Spencer family, detailing its construction, the lives of its inhabitants, and its role in British history.
* The Lost King of the Lost City: The Epic Tale of a Royal Secret (2022): A compelling historical narrative about the story of King Richard III and the discovery of his remains beneath a car park in Leicester.
Other Works:
* The Royals: An Illustrated History (2011): This book offers a visual history of the British monarchy, spanning centuries of royal reigns.
* Kingmaker: The Life of Richard III (2014): A biographical account of the life of Richard III, focusing on his role as a political figure and his controversial legacy.
Charles Spencer has also written numerous articles and essays for publications such as The Daily Telegraph, The Sunday Times, and Vanity Fair.