Dr Watson’s first name in the Sherlock Holmes stories is John.
John Watson is Sherlock Holmes’s friend, colleague, and principal narrator. He is a physician and former army doctor who served in the Second Anglo-Afghan War before returning to London. Watson meets Holmes in A Study in Scarlet, where their need for affordable lodgings leads them to share rooms.
Watson’s narration allows readers to discover cases alongside him. He often admires Holmes’s deductions while admitting that he cannot always follow the chain of reasoning immediately. Watson is also an active participant: he carries out investigations, provides medical knowledge, and sometimes protects Holmes in dangerous situations.
Some adaptations create confusion about Watson’s name. In the original canon, he is John H. Watson, although the middle initial is not consistently explained. The television series Sherlock famously uses “James” as part of a joke about the initials J.W., but that is an adaptation detail, not Watson’s canonical first name.