Claim: James Wilson is a fictional character.

Dr. James Evan Wilson , M.D. , is a fictional character on the Fox medical drama House . He is played by Robert Sean Leonard . The character first appears in the show 's pilot episode when he introduces a medical case to Dr. Gregory House . Wilson is Dr. House 's only true friend , and frequently provides him with consultations and aid . Wilson is the head of the Department of Oncology at Princeton-Plainsboro Teaching Hospital .   During the show 's run , the characters of House and Wilson have been compared to Sherlock Holmes and Dr Watson . Wilson 's portrayer , Robert Sean Leonard , has stated that his character and Dr. House were originally supposed to play these roles ; but Dr. House 's diagnostic team has taken over Dr. Watson 's part . Leonard also read the script of the pilot episode of CBS ' Numb3rs and was planning to audition . He auditioned for House instead because he felt he would more enjoy playing the character that House went to for help and because he liked The Odd Couple dynamic of the relationship .   The character was positively received . Alan Sepinwall of The Star-Ledger described Wilson as `` the only irreplaceable supporting character '' of the show , as well as Maureen Ryan of the Chicago Tribune , who stated that Wilson can `` never , never , never , never '' leave the show .   The character 's name is derived from two neighboring buildings -LRB- James Administration Building and Wilson Hall -RRB- at McGill University 's downtown campus , in Montreal , Quebec .