He called it "insane" why anyone would leave a successful band and go solo.
The One Direction star mimicked the Rolling Stone frontman for a sketch on the U.S. comedy show, where he also showcased some of his new music. He also brought a sharp suit, his Bowie-esque vocals, and some Beatles-style bass lines to the April 15 episode.
The last time Timberlake and Fallon appeared on SNL was during the comedy show's 40th anniversary, which Fallon kicked off with a grand musical performance that was instantly overshadowed when Timberlake interrupted.
But where Styles stretched his acting legs the most was during the special time travel edition of "The Family Feud".
Throughout the five minute sketch Harry stayed in character, pulling off Jagger-like facial impressions and even throwing his hands up in the air like the legendary star.
Wall Street's bull sculptor wants 'Fearless Girl' moved
Di Modica's bull has become a familiar icon since he gave it to the city in 1989. Speaking of his own work, he added "My bull is a symbol for America".
The thing about Jimmy Fallon returning to his old stomping grounds to host "Saturday Night Live" is that it's become kind of a roller coaster from moment to moment.
Melissa McCarthy returned to Saturday Night Live in her role as White House Press Secretary Sean "Spicey" Spicer, this time in Easter Bunny garb. He sang and danced for a few seconds with Jimmy Fallon, and although it was very brief - clearly Hazza was ready to make audiences laugh.
It was the first time in SNL's history that the show was broadcast simultaneously across all time zones in America.
When SNL announced that Harry was due to appear on the show, we instantly started countding down the days.well, the wait was worth it!
Yep, it safe to say Harry Styles killed it on Saturday Night Live last night. According to NBC, SNL was broadcast live in all time zones across the US and Canada for the first time.