What is the name of House’s closest friend in House M.D.?

House’s closest friend in House M.D. is Dr. James Wilson.

Robert Sean Leonard played Wilson, an oncologist who works at the same teaching hospital as House. Wilson is one of the few people willing to challenge House consistently while still understanding his unusual reasoning and complicated personality.

Their friendship is central to the series. Wilson often acts as House’s moral counterweight, translating the consequences of House’s decisions for colleagues, patients, and friends. The pair’s relationship also mirrors the partnership between Sherlock Holmes and Dr. Watson, one of the show’s deliberate literary parallels.

Wilson’s specialty is oncology, the study and treatment of cancer. This is distinct from House’s role as a diagnostician, whose department investigates difficult cases that may involve many medical specialties.