In House M.D., House’s closest friend is the oncologist Dr. James Wilson.
James Wilson is played by Robert Sean Leonard and serves as the head of oncology at Princeton-Plainsboro Teaching Hospital. His medical specialty places him in charge of diagnosing and treating cancer, while his personal role in the series is to challenge, support, and sometimes enable House.
Wilson and House have a long, complicated friendship. Wilson often acts as House’s moral counterweight, but he also understands House’s intelligence and loneliness better than most of the hospital staff. Their conversations provide the series with a way to examine House’s behavior beyond the immediate medical puzzle.
The surname is Wilson, while the character’s full name is James Evan Wilson. He should not be confused with Lisa Cuddy, the hospital dean, or Eric Foreman and Robert Chase, members of House’s diagnostic teams. Robert Sean Leonard played Wilson throughout the series, but the answer requested is the character’s surname.