Sherlock Holmes (/ˈʃɜrlɒk ˈhoʊmz/) is a fictional character created by Scottish author and physician Sir Arthur Conan Doyle, a graduate of the University of Edinburgh Medical School. A London-based "consulting detective" whose abilities border on the fantastic, Holmes is known for his astute logical reasoning, his ability to adopt almost any disguise and his use of forensic science to solve difficult cases.

Holmes, who first appeared in print in 1887, was featured in four novels and 56 short stories. The first novel, A Study in Scarlet, appeared in Beeton's Christmas Annual in 1887 and the second, The Sign of the Four, in Lippincott's Monthly Magazine in 1890. The character's popularity grew with the first series of short stories in The Strand Magazine, beginning with "A Scandal in Bohemia" in 1891; additional short-story series and two novels (published in serial form) appeared from then to 1927. The events in the stories take place from about 1880 to 1914.

All but four stories are narrated by Holmes's friend and biographer, Dr. John H. Watson. Two are narrated by Holmes himself ("The Adventure of the Blanched Soldier" and "The Adventure of the Lion's Mane"), and two others are written in the third person ("The Adventure of the Mazarin Stone" and "His Last Bow"). In two stories ("The Adventure of the Musgrave Ritual" and "The Adventure of the Gloria Scott"), Holmes tells Watson the story from memory, with Watson narrating the frame story. The first and fourth novels, A Study in Scarlet and The Valley of Fear, include long passages of omniscient narrative of events unknown to either Holmes or Watson.