The series of promos begins with Fallon and Styles playfully jockeying for position while a jazzy score plays in the background.
They then proceed to show off their rhythm in a pair of promos that feature them walking snapping toward the camera as they snap their fingers.
The pair are eerily silent through the first of the two promos, perhaps because the second features Fallon and Styles struggling to contain their laughter as they set up the show.
Fallon, a former SNL cast member, will host the show for the first time since 2013 while Styles will be the musical guest for the first time since branching out from One Direction to launch a solo career.
Styles, 23, is set to release his first self-titled solo album on May 17, featuring the single "Sign of the Times."
The April 15 SNL episode will also serve as a historic moment for Saturday Night Live, as the show will broadcast simultaneously from coast to coast for the first time.