Sherlock Holmes is a fictional private detective created by British author Sir Arthur Conan Doyle. Referring to himself as a "consulting detective" in the stories, Holmes is known for his proficiency with observation, deduction, forensic science, and logical reasoning that borders on the fantastic, which he employs when investigating cases for a wide variety of clients, including Scotland Yard.

Though not the first fictional detective, Sherlock Holmes is arguably the best known.By the 1990s there were already over 25,000 stage adaptations, films, television productions and publications featuring the detective, and Guinness World Records lists him as the most portrayed literary human character in film and television history.[3] Holmes's popularity and fame are such that many have believed him to be not a fictional character but a real individual;numerous literary and fan societies have been founded on this pretense. Avid readers of the Holmes stories helped create the modern practice of fandom.The character and stories have had a profound and lasting effect on mystery writing and popular culture as a whole, with the original tales as well as thousands written by authors other than Conan Doyle being adapted into stage and radio plays, television, films, video games, and other media for over one hundred years.