- Memorabilia, such as statuettes, drawings, and movie posters, that concern the fictional character Sherlock Holmes, his associates such as Dr. Watson and Inspector Lestrade, and his dwellings at 221B Baker Street;
- Non-canonical fiction, not written by Sir Arthur Conan Doyle, that relates to these characters and their world;
- References in fiction, as when characters from other fictional settings refer to the Sherlock Holmes stories as stories; and
- The Sherlockian game, the pastime of attempting to resolve anomalies and clarify implied details about Holmes and Watson.
As such, Sherlockiana ranges from serious treatments of the character such as the novel The Seven-Per-Cent Solution by Nicholas Meyer, to outright parody such as the recording The Tale of the Giant Rat of Sumatra by the Firesign Theatre and Gene Wilder's The Adventure of Sherlock Holmes' Smarter Brother. Shows such as CSI will sometimes refer to Holmes or use Holmes-like imagery in their mysteries.
The "Encyclopaedia Sherlockiana", published in 1979, is a reference text that contains an exhaustive list of over 3,500 people, places, and things associated with the universe of Sherlock Holmes. It expands Doyle's world by including non-canonical details from other authors as well.
Charles Spencer, former theater critic for The Daily Telegraph, used the term to refer to the 2009-12 releases of The House of Silk, Sherlock (TV series), and the two Sherlock Holmes films (Sherlock Holmes and A Game of Shadows), as representative of a "golden age of Sherlockiana."
- "Sherlockiana". The Conan Doyle Encyclopedia. Retrieved 19 November 2015.
- Morley, Christopher; Steven Rothman (1990). "Notes on Baker Street". The Standard Doyle Company: Christopher Morley on Sherlock Holmes. Fordham Univ Press. pp. 68–71. ISBN 978-0-8232-1292-7.
- Huntley, Kristine (11 January 2005). "CSI Files - CSI: Crime Scene Investigation--'Who Shot Sherlock?'". CSI Files. Retrieved 19 November 2015.
- "The Encyclopaedia Sherlockiana; or, A Universal Dictionary of the State of Knowledge of Sherlock Holmes and His Biographer, John H. Watson, M.D. - Paperback – January 1, 1979". Amazon. Retrieved 19 November 2015.
- Spencer, Charles (19 December 2011). "Sherlock Holmes: we are living in a golden age of Sherlockiana". The Daily Telegraph. Retrieved 19 November 2015.
- The Baker Street Journal, an Irregular Quarterly of Sherlockiana
- Sherlock Holmes and Sherlockiana Collection at the Harry Ransom Center Digital Collections