Stuart is a professor at Pennbrook who has Shawn, Angela, Cory, and Topanga in his class. He teaches them about fate and destiny, and believes about them. He is very friendly, making jokes about his students (he mocks Shawn's haircut) and giving them nicknames (he calls Cory "Romeo"). Shawn really likes him, saying he treats them like adults.
Everyone begins to dislike him when he makes a move on Topanga, and then fights with Cory over it. According to Cory, Stuart refused to stop and said there was nothing Cory could do, making Cory strike him. At Cory's hearing, Dean Bolander said that while Mr. Feeny was a teacher, Stuart was not, and that she intended to find out what he truly was.
Trivia: The actor portraying Stuart is the brother of the actor that plays Cory.