<P> The Tonight Show is an American late - night talk show currently broadcast from the NBC studios in Rockefeller Center in New York City (and previously from various studios in the Los Angeles region) and airing on NBC since 1954 . It is the world's longest - running talk show, and the longest running, regularly scheduled entertainment program in the United States . It is the third - longest - running show on NBC, after the news - and - talk shows Today and Meet the Press . </P> <P> Over the course of more than 60 years, The Tonight Show has undergone only minor title changes . It aired under the name Tonight for several of its early years, eventually settling on The Tonight Show after the seating of long - time host Johnny Carson in 1962 . In later decades, network programmers, advertisers, and the show's announcers would refer to the show by including the name of the host; for example, it is currently announced as The Tonight Show Starring Jimmy Fallon . In 1957, the show briefly tried a more news - style format . It has otherwise remained a talk show throughout its run . </P> <P> The Tonight Show began broadcasting in 1954 . It has had six official hosts, beginning with Steve Allen (1954--57), followed by Jack Paar (1957--62), Johnny Carson (1962--92), Jay Leno (1992--2009, 2010--14), Conan O'Brien (2009--10), and Jimmy Fallon (2014--present). It has had several recurring guest hosts, a practice especially common during the Paar and Carson eras . </P> <P> Carson is the longest - serving host to date . The Tonight Show Starring Johnny Carson aired for 30 seasons between October 1962 and May 1992 . Leno, however, has the record of having hosted the greatest number of total televised episodes . Leno's record accounts for the fact that unlike Carson (who only produced new shows three days a week starting in the 1980s), Leno never used guest hosts (except Katie Couric, once) and produced new shows five days a week; Leno himself was also Carson's primary guest host for the last five years of Carson's tenure, giving him even more episodes to his credit . During Johnny Carson's first eighteen years, the show ran for ninety minutes . During Johnny's 1980 contract negotiations, the show was shortened to sixty minutes . NBC also broadcast The Best of Carson which were repeats of some of Johnny's popular older shows . Prior to the debut of Saturday Night Live in October of 1975, NBC aired The Best of Carson on Saturday nights at 11: 30 pm . </P>

Who replaced johnny carson on the tonight show