The Tonight Show is an American late-night talk and variety show airing on NBC since 1954. Tonight is the third longest-running entertainment program in U.S. television history, after Guiding Light and Hallmark Hall of Fame.

The Tonight Show has been hosted by Steve Allen (1954–1957), Jack Paar (1957–1962), Johnny Carson (1962–1992), Jay Leno (1992–2009), and Conan O'Brien (2009–present). The longest-serving host to date was Carson, who hosted The Tonight Show Starring Johnny Carson for 30 seasons, from the fall of 1962 through the spring of 1992.