Harry Styles Gets Wish Granted by Stevie NicksIn addition to acting on the show, Styles talked about the role he played in the upcoming movie, Dunkirk, which opens in theaters Friday (July 21).
Watch Liam Payne Perform 'Strip That Down' on 'The Tonight Show'The performance featured backup dancers in a big neon frame and Payne gave a shoutout to the talk show host.
Watch Lil Yachty Rap about 'The Simpsons'"You’ve got Homer, Marge, Lisa and Bart/ You got Maggie and Santa’s Little Helper to start."
Watch Niall Horan Try to Write a Song about 'Quickly Clicky Pens'Horan and Jimmy Fallon have fun in the segment 'Instant Song Challenge.'
Watch Harry Styles and Jimmy Fallon's Snappy New SNL PromoThis will be the first time the show has been aired live on the East and West Coast.
Demi Lovato and Jimmy Fallon Play Teen Girls in "Ew!' SketchDemi held her own in the comedy department, practicing kissing on an Ed Sheeran pillow (Fallon's had Mario Lopez's face on it).
Jennifer Lopez Struts Her Stuff in Silly Dance Battle on 'Fallon'Fallon went first, making up a silly dance called, “Skinny Jeans.” Lopez proceeded to show him up with a very J.Lo version of “Washing Machine Spin Cycle.”
Watch Niall Horan Perform 'This Town' on 'The Tonight Show'Horan is the second member of One Direction to play solo on the program. Zayn Malik performed “It’s You,” from 'Mind of Mine' in February.
Justin Timberlake Joins Jimmy Fallon at Camp in 'Tonight Show' SkitIn a room surrounded by childhood games of the '90s like Guess Who? and Battleship, the two friends decide to sing a song they heard on the radio earlier that day -- "Ironic" by Alanis Morissette.
Sarah Paulson Raps Salt N' Pepa On FallonSarah Paulson has skills!
Shawn Mendes Pokes Fun of Jimmy Fallon on 'The Tonight Show'Mendes couldn't help calling Fallon a "grandpa" and reminding the host about their age difference.
Ariana Grande Flawlessly Sings "Jason's Song" On "The Tonight Show With Jimmy Fallon"Ariana sported her signature massive ponytail and something new were gold rimmed glasses from what appears to be the 80s.