Garrett was initially successful as a stand-up comedian in the early 1980s. Taking advantage of that success in the late 1980s, Garrett began appearing in television and film, in minor and guest roles. His first major role was Robert Barone on the CBS sitcom Everybody Loves Raymond. The series debuted September 13, 1996 and ran for nine seasons. In 2002, he gave an Emmy-nominated and critically lauded performance as Jackie Gleason in the television film Gleason.