The Tonight Show Starring Jimmy Fallon Season 5 John Lithgow, Kelly Clarkson, Kacey Musgraves Season 5, episode 78 John Lithgow, Kelly Clarkson, Kacey Musgraves February 26, 2018 45 min Previous episode Paul Rudd, Laurie Metcalf, Alice Merton Next episode Bruce Willis, Retta, Towkio