Sherlock Holmes' assistant is Dr. John H. Watson, a character created by Sir Arthur Conan Doyle. Watson serves not only as Holmes' confidant and companion but also as the narrator of many of the stories. A former army doctor, Watson brings a practical perspective to the investigations and often contrasts Holmes' brilliant but eccentric methods. Throughout the series, their friendship grows, and Watson's loyalty and admiration for Holmes are evident. Together, they solve complex mysteries, making their partnership one of the most iconic in literary history.