<P> On April 3, 2013, after a dispute with the network over Leno's joking about the network's poor prime time performance in his monologues, NBC announced that Leno would retire in 2014, with Late Night host Jimmy Fallon taking over The Tonight Show after the conclusion of NBC's coverage of the 2014 Winter Olympics . It was Leno's suggestion to use NBC's coverage of the Olympics as a springboard for Fallon's tenure . The date was later moved up a week to February 17, midway through the Olympics . </P> <P> Leno's last Tonight Show aired on February 6, 2014, featuring guests Billy Crystal (Leno's first guest in 1992) and Garth Brooks . Leno gave a tearful goodbye at the end of the program, calling himself "the luckiest guy in the world", and reflecting on his time as host as "the greatest 22 years of my life ." He happily moved forward into an online series about his famous hobby, automobiles (like Jerry Seinfeld, he owns aircraft hangars filled with hundreds of cars that he works on and drives), entitled Jay Leno's Garage, and also continues to perform live stand - up comedy . </P> <P> Jimmy Fallon (who had hosted The Tonight Show's follow - up show, Late Night, since 2009) assumed The Tonight Show hosting role on February 17, 2014, with his initial guests being Will Smith and the rock band U2, plus an assortment of celebrity cameos, including an appearance by one of Fallon's direct broadcast competitors, Stephen Colbert, and another by former permanent guest host Joan Rivers, making her first appearance on Tonight since cutting ties with Carson in 1986 . The show's opening sequence was directed by filmmaker Spike Lee . </P> <P> As part of the transition to Fallon, The Tonight Show would be brought back to New York City after 42 years in Southern California . Approximately $5 million was budgeted to renovate Studio 6B, where Fallon recorded Late Night . The move also enabled NBC to take advantage of a newly enacted New York state tax credit for talk shows that are "filmed before a studio audience of at least 200, as long as they carry a production budget of at least $30 million and have been shot outside New York for at least five seasons ." Studio 6B is also where Jack Paar hosted The Tonight Show . Johnny Carson hosted The Tonight Show there for ten years before the show was moved to Burbank in 1972 . Lorne Michaels (the producer of Saturday Night Live, in which Fallon appeared prior to hosting Late Night) became executive producer of The Tonight Show . </P>

Who was the youngest when they became the full-time host of the tonight show