Reginald Evelyn Peter Southouse-Cheyney was a British crime fiction writer who flourished between 1936 and 1951. Cheyney is perhaps best known for his short stories and novels about agent/detective Lemmy Caution, which, starting in 1953, were adapted into a series of French movies, all starring Eddie Constantine. Another popular creation was the private detective Slim Callaghan who also appeared in a series of novels and subsequent film adaptations.