Hall joined the cast of "Saturday Night Live (SNL)" during its 1985–86 season at the age of 17. He was, and remains, the youngest cast member in the show's history. His recurring characters on the show were Craig Sundberg, Idiot Savant, an intelligent, talented teenager with a vacant expression and stilted speech, and Fed Jones, half of the habitually high, hustling pitchmen known as The Jones Brothers. Art Garfunkel, Edd Byrnes, Robert F. Kennedy, and Daryl Hall were among Hall's celebrity impersonations. Hall had admired the show and its stars as a child, but he found the "SNL" environment to be far more competitive than he had imagined. "My year there, I didn't have any breakout characters and I didn't really do the things I dreamed I would do," he said, "but I still learned a lot and I value that. I'll always be proud of the fact that I was a part of its history." Hall was one of six cast members (the others being Joan Cusack, Robert Downey, Jr., Randy Quaid, and Terry Sweeney) who were dismissed at the end of that season.