The Secret Battle is a novel by A. P. Herbert, first published in 1919. The book draws upon Herbert's experiences as a junior infantry officer in the First World War, and has been praised for its accurate and truthful portrayal of the mental effects of the war on the participants. It was one of the earliest novels to contain a detailed description of Gallipoli, and to challenge the Army's executions of soldiers for desertion. It is noticeable as being sharply different from Herbert's later work—there is no note of humour or lightness in the novel, simply a stark and simple narrative.