"Adore You" arrives after last month's "Watermelon Sugar" and October's lead single "Lights Up".
Earlier this week, Styles dropped the trailer for "Adore You", which confirmed the singer and his team's link to the fake tourism account Eroda.
Today (6 December), Styles has unveiled the Dave Meyers-directed video for the new single, which sees Rosalía tell the tale of the non-existent island of Eroda around Styles' new song.
Fine Line will follow on from Styles' 2017 self-titled debut album.
Back in August Styles revealed that his second album is about "having sex and feeling sad", and added that he did "a lot of mushrooms" while in Malibu's Shangri-La studios.
