Dr. James Wilson is the head of the oncology department at Princeton-Plainsboro Teaching Hospital. He's Dr. Gregory House's best, and arguably only, friend. His bedside manner might be described as the opposite of House's: compassionate, interested, and empathetic.

Wilson and House's friendship dates back many years and has been sorely tested on several occasions. Wilson was voted off the hospital board and had his bank accounts frozen for his allegiance to House; in neither case did his friend seem particularly remorseful or grateful for the loyalty shown him.

The breaking point came after the death of Wilson's girlfriend, Amber Volakis, who was killed while attending to a drunken House. Wilson didn't blame House for Amber's death, but he felt that House was a toxic presence in his life, and so he cut off all contact with his friend. However, he didn't stay away long, admitting that he does enjoy being around House, despite his misanthropic tendencies.

Married three times, Wilson recently began a relationship with his second ex-wife, Sam. But a fight over trust convinced Sam that while she had grown during their time apart, Wilson hadn't, and she left him.

House regularly seeks Wilson's counsel, particularly over issues concerning the hospital's Dean of Medicine, Dr. Lisa Cuddy, though many times the rational, thoughtful advice Wilson imparts is lost on House, who tends to hear what he wants to hear. Wilson may have unwittingly helped direct House toward his catastrophic crash through Cuddy's living room, when he encouraged House to express his anger over their breakup, rather than keep it bottled up.