In House M.D., who is Dr. Gregory House's best friend and an oncologist?

In House M.D., Dr. Gregory House’s best friend and oncologist is James Wilson.

Dr. James Evan Wilson heads the oncology department at Princeton-Plainsboro Teaching Hospital. He is one of the few people who consistently understands House’s behavior while still challenging his decisions, making their friendship one of the show’s central relationships.

Wilson’s medical specialty is oncology, the branch of medicine concerned with cancer. His work gives the series a contrasting perspective: House focuses on solving rare diagnostic puzzles, while Wilson frequently deals with long-term illness, difficult treatment choices, and end-of-life care.

Robert Sean Leonard played Wilson throughout the series. The character is sometimes confused with House’s colleagues in the diagnostic department, but Wilson is not a member of House’s regular diagnostic team. His separate role and personal loyalty help connect House’s professional life with the wider hospital community.