In the Sherlock Holmes stories, what is the address of Holmes and Watson's flat?

In the Sherlock Holmes stories, Holmes and Watson’s flat is at 221B Baker Street.

The address is Sherlock Holmes’s fictional London residence, where Dr. John Watson also lives for much of the early narrative. It first appears in Arthur Conan Doyle’s 1887 novel “A Study in Scarlet.” The rooms are traditionally imagined as a sitting room and study on the first floor, reached by a staircase of 17 steps.

The letter “B” is important: it indicates a separate residence within a larger building rather than a different street. Doyle’s stories portray the apartment as the base where Holmes interviews clients, studies clues, experiments, and receives messages about cases.

A frequent mix-up is 221A Baker Street, which is used in some adaptations for Watson or other occupants. The address is fictional in its original literary setting. When Baker Street’s numbering was later extended, real buildings associated with 221B became entangled in a long-running dispute involving Abbey National and the Sherlock Holmes Museum.