Dr. James Evan Wilson is the head of the Department of Oncology at Princeton-Plainsboro Teaching Hospital. He is one of three brothers from a Jewish household. He has an undergraduate degree from McGill University as well as graduate degrees from Columbia and the University of Pennsylvania.
Shortly after a medical convention in New Orleans, Wilson accidentally broke an antique mirror and started a bar fight with a random man who repeatedly played Billy Joel's "Leave A Tender Moment Alone". Wilson was going through his first divorce at the time. Out of interest, House bailed him out and hired an attorney to clear Wilson's name which in turn started their professional relationship. It's revealed in Season 1 that one of Wilson's brothers is homeless and he is unaware if he's still alive as he hadn't seen him in nine years. Wilson has a history of failed marriages. During Season 1, Wilson is married to his third wife but after discovering her infedility, he seperated from her during the course of Season 2. He went on to live in a series of temporary accommodations (including House's apartment) until he met Amber Volakis, the female substitute for House. During a date with Dr. Lisa Cuddy, Wilson evaded a question as to whether or not he wanted children. In Season 3, Wilson is shown to suffer from severe depression and is also left-handed, something he shares with both Cuddy and Foreman.
Wilson is described as "a buddy of mine who people say 'Thank You' to when he tells them they're dying" by House. House also described him as an 'emotional vampire'.
Wilson's friendship with House has been severely tested over the course of the show.
He defended House when his career was in jeopardy, after billionaire entrepreneur and chairman of the hospital board, Edward Vogler proposed a dismissal. Wilson was the only one to vote against the proposal. In response, Vogler proposed Wilson's dismissal but he was reinstated thanks to Cuddy convincing the board that Vogler was the real threat to the hospital. Wilson attempted to change House's drug habits with little success. After Cuddy made a bet that House was addicted to Vicodin, House conceded to Wilson that he did have an addiction but it wasn't a problem. It was Wilson who continually wrote the Vicodin prescriptions to House. In Season 3, when Detective Michael Tritter threatened to jail House for his Vicodin addiction, Wilson attempted to convince House to enter rehab.
Wilson stood and watched House punch Chase, insult Cuddy and misdiagnose a child with a condition that would have needed one of her legs and arms amputated. After Tritter pressured Wilson to testify numerous times, Wilson agreed reluctantly and unknowingly to House.
Near the end of Season 4, Wilson began a romantic relationship with Amber Volakis, as she was a female version of House. In the season finale, Amber was killed in a bus crash sustained when she went to pick up a drunken House from a bar. Her death eventually led Wilson to conclude that his friendship with House only worked because it served House's dysfunctions. To remove himself from House's influence, Wilson resigned from Princeton-Plainsboro at the beginning of Season 5. The two reconciled when Wilson forced House to attend his father's funeral. Wilson then realized that he was afraid of losing House, his only true friend and that his life hadn't been any better since he'd resigned. Wilson then returned to Princeton-Plainsboro.
During Season 5, Danny (one of Wilson's brothers who was mentioned as being homeless) is revealed to have suffered from schizophrenia since adolescence which caused him to run away in the first place. Wilson blamed himself for his brother's homelessness as he hung up on him shortly before his disappearance. He also revealed that he'd taken the job at Prineton-Plainsboro because it was close to the last place he'd seen Danny. When Wilson found out that Danny was on the psych ward, House offered to come with him, noting that it could end badly. However, when Wilson was let in to see his brother, House was busy with his team.
Wilson is played by Robert Sean Leonard.