"The Facts in the Case of M. Valdemar" is a short story by the American author Edgar Allan Poe about a mesmerist who puts a man in a suspended hypnotic state at the moment of death. An example of a tale of suspense and horror, it is also to a certain degree a hoax, as it was published without claiming to be fictional, and many at the time of publication (1845) took it to be a factual account. Poe admitted it to be a work of pure fiction in letters to his correspondents.

Edgar Allan Poe was an American writer, poet, author, editor, and literary critic who is best known for his poetry and short stories, particularly his tales of mystery and the macabre. He is widely regarded as a central figure of Romanticism and Gothic fiction in the United States, and of American literature. Poe was one of the country's earliest practitioners of the short story, and is considered the inventor of the detective fiction genre, as well as a significant contributor to the emerging genre of science fiction. He is the first well-known American writer to earn a living through writing alone, resulting in a financially difficult life and career.