An Officer and a Spy is a 2013 historical fiction thriller by the English writer and journalist Robert Harris. It tells the true story of the French officer Georges Picquart from 1896 to 1906, as he struggles to expose the truth about the doctored evidence that sent Alfred Dreyfus to Devil's Island.

Robert Dennis Harris is a British novelist and former journalist. Although he began his career in journalism and non-fiction, his fame rests upon his works of historical fiction. Beginning with the best-seller Fatherland, Harris focused on events surrounding the Second World War, followed by works set in ancient Rome. His most recent works centre on contemporary history.