In House M.D., what is the name of Gregory House's longtime best friend?

In House M.D., Gregory House's longtime best friend is Dr. James Wilson.

Wilson is an oncologist at Princeton-Plainsboro Teaching Hospital and is played by Robert Sean Leonard. His professional relationship with House places him close to the diagnostic department while giving the series a contrasting personality: Wilson is generally more empathetic, socially skilled, and willing to challenge House's behavior.

The friendship is central to the show's emotional structure. Wilson frequently helps House interpret personal problems, although House's manipulation and disregard for boundaries repeatedly strain their relationship. Their bond survives arguments, professional conflicts, and several serious personal crises.

A common mistake is to identify Omar Epps's character, Eric Foreman, as House's closest friend. Foreman is instead one of House's doctors and later becomes a hospital leader. Wilson remains the show's principal friend and confidant.