Who played James Wilson, House’s best friend, in House M.D.?

Robert Sean Leonard played James Wilson in House M.D.

Wilson is an oncologist and the closest friend of Gregory House. His empathy and professional judgment frequently contrast with House’s sarcasm, risk-taking, and disregard for conventional authority. Wilson often acts as House’s confidant, defender, and moral counterweight.

Leonard was already known for film and stage work before joining the series. His earlier credits included Dead Poets Society, while his later career continued to include theater and television. House M.D. gave him a long-running dramatic role built around a complicated friendship rather than medical mysteries alone.

James Wilson is sometimes mistaken for a member of House’s diagnostic team. He is not one of the original fellows; he is the head of oncology and a separate senior physician. His friendship with House becomes one of the show’s most important continuing relationships.