The Baker Street Irregulars is a group of street urchins and young boys in the Sherlock Holmes stories. They play a significant role in several of the detective's investigations and are often called upon by Sherlock Holmes to gather information or conduct surveillance in situations where his presence might be too conspicuous.
The name "Baker Street Irregulars" comes from their base of operations, as they are based in the vicinity of Sherlock Holmes and Dr. Watson's residence at 221B Baker Street in London. The group is essentially a network of street-smart children who know the ins and outs of the city and can move around discreetly, making them invaluable to Holmes in gathering information from the streets.
Holmes maintains a friendly relationship with the Baker Street Irregulars, and he occasionally pays them for their assistance in his cases. He is known to interact with them in person or communicate through their leader, a young boy named Wiggins.
The Baker Street Irregulars first appeared in "A Study in Scarlet," the debut Sherlock Holmes novel, and subsequently made appearances in other stories. They became an endearing and memorable aspect of the Sherlock Holmes canon, showcasing Holmes' resourcefulness in utilizing the skills of people from various walks of life to aid in his detective work.