Which character is the oncologist and best friend of House in House M.D.?

James Wilson is House’s oncologist colleague and best friend in House M.D.

Wilson works at Princeton-Plainsboro Teaching Hospital and specializes in oncology, the branch of medicine concerned with cancer. His medical specialty frequently places him in contact with seriously ill patients, while his personal connection to House makes him central to the show’s emotional story.

Wilson and House have very different personalities. Wilson is generally empathetic and cooperative, whereas House is deliberately provocative and suspicious of easy explanations. Their friendship survives repeated arguments, betrayals, and professional complications, although it is never presented as simple or entirely healthy.

Robert Sean Leonard plays Wilson. The character is not the hospital administrator, the diagnostic-team leader, or a surgeon. Those distinctions matter because House M.D. includes several recurring physicians whose roles and specialties overlap in the hospital setting.