The Baker Street Irregulars

The oldest Sherlock Holmes society is the Baker Street Irregulars, founded in 1934 by Christopher Morley. Membership—in contrast to the custom for practically all other Sherlockian societies—is by invitation only. The major event is an annual January dinner in New York, the centrepiece of the annual "birthday weekend" that brings hundreds of Sherlockians to New York.

The BSI has dozens of "scion societies" across the United States, and kindred societies in other countries. It publishes the quarterly Baker Street Journal.

• Al Gregory's list of Irregulars, arranged by Investiture (on Sherlockian.Net)
• The Baker Street Irregulars Trust
• A band that shares nothing except the name
• BSI Archival History and Blog
• Canadian Baker Street Irregulars
• Finding aid for archives at Harvard University
• The Junior Sherlockian Society
• Lyndsay Faye explains the BSI's January weekend and explains why the BSI is not a fandom

United States

Central

• The Afghanistan Perceivers (Tulsa, Oklahoma)
• The Agra Treasurers (Dayton, Ohio)
• Amateur Mendicant Society of Detroit
• The Crew of the Barque Lone Star (Dallas, Fort Worth)
• Criterion Bar Association, Chicago
• Diogenes Club of Dallas
• The Giant Rats of Sumatra (Memphis, Tennessee)
• The Greek Interpreters (East Lansing, Michigan)
• The Hansoms of John Clayton, Peoria
• The Hated Rivals on the Surrey Shore (Indianapolis)
• The Hounds of the Baskerville [sic] (Chicago)
• Illustrious Clients of Indianapolis
• John Openshaw Society, Houston
• Maiwand Jezails (Omaha)
• Nashville Scholars
• The Norwegian Explorers (Minnesota)
• The Notorious Canary-Trainers (Madison, Wisconsin)
• Occupants of the Empty House (southern Illinois)
• The Original Tree Worshippers of Rock County (Wisconsin)
• Parallel Case of St. Louis
• The Younger Stamfords (Iowa City)

East

• The Avenging Winters of Albany
• The Baker Street Breakfast Club, Vermont
• The Hansom Wheels, Columbia, South Carolina
• Mrs. Hudson's Cliffdwellers, New Jersey
• Mrs. Hudson's Lodgers
• The Pleasant Places of Florida
• Priory Scholars of New York
• The Red Circle of Washington
• A Scintillation of Scions
• Sherlock Holmes Club
• Sherlock Holmes Meetups
• Sherlock Holmes Pipe Club of Boston
• Society of the Naval Treaty (Annapolis)
• Three Garridebs of Westchester County
• Watson's Tin Box (Maryland)
• White Rose Irregulars (York, Pennsylvania)

West

• The Blustering Gales from the South-West
• Curious Collectors of Baker Street (Los Angeles)
• Dr. Watson's Neglected Patients (Denver)
• The Noble and Most Singular Order of the Blue Carbuncle, Portland, Oregon
• The Sherlock Breakfast Club (Los Angeles)
• The Sound of the Baskervilles (Washington state)