Directed by Bradley & Pablo and filmed in Malibu, California, it features Styles alongside a plethora of people dancing on the beach and eating watermelon.

"Watermelon Sugar" was written by Styles, Mitch Rowland, and producers Tyler Johnson and Kid Harpoon.

[5][6] The song was first teased by Styles in a 22 October 2019 tweet writing "Kiwi walked so Watermelon Sugar could run.

[18] Driven by guitars and horns, the song also contains brass lines, summer-inflected sonics and a simple melody, reminiscent of jazz.

[23] Trumpets are added in the second chorus, that builds up to the bridge, featuring ecstatic horns and high notes.

[28] Savannah Walsh of Elle wrote about the song's meaning, asking the question "[is he] hankering for a refreshing summer treat or [is he] talking about cunnilingus," while USA Today's Patrick Ryan interpreted it as "Styles evocatively [recalling] a past fling and its sweet aftertaste.

[31] In a positive review from USA Today, Patrick Ryan called it a "intoxicating standout" on Fine Line, writing that it "[encapsulates] the sultry, funky spirit of the project.

"[32][20] In her review for Rolling Stone, Brittany Spanos wrote "the track has the singer nostalgic for 'that summer feeling,' yearning for berries and the taste of watermelon sugar".

[34] Paste's Ellen Johnson called it Fine Line's most "traditional" song as well as comparing its bassline to Prince.

[36] In a negative review from Consequence of Sound, Bryan Rolli called the song "plodding", while also writing it "commits the cardinal sin of being far less interesting than its title.

"[37] Owen Richards of The Arts Desk also gave a negative review, calling its imagery "nonsensical," writing that it "misses the mark.

After the release of Fine Line, "Watermelon Sugar" debuted at number thirty-eight on the ARIA singles chart in Australia; later reaching a new peak of twelve in its fifth week.

In the United States, "Watermelon Sugar" debuted at number sixty on the Billboard Hot 100 chart dated 30 November 2019.

He also became the second member of One Direction to reach number one on the Billboard Hot 100 after Zayn Malik with his 2016 hit "Pillowtalk".

The video was inspired by Paul McCartney's 1960s style and was partly filmed using a 35 and 16 mm Arri SR3 camera to make some shots look vintage.

[64] He wears an orange crochet tank, oversized blue sunglasses, bubblegum pink nail polish and his signature "HS" rings.

[69] Styles wears a cropped striped sweater, a skinny fringe scarf and a pair of vintage-inspired ripped jeans, all of which come from Gucci's fall 2020 collection.

"[66] In her review for Entertainment Weekly, Rosy Cordero wrote "Harry Styles is wishing he was back on the beach surrounded by beautiful people, deliciously colorful fruits, and no coronavirus.

"[57][65] Writing for NME, Will Lavin described the video as "Styles [throwing] a beach party with a group of women, who can all be seen eating watermelon throughout.

"[76] Alisha Pawa of Lifestyle Asia called the video "light-hearted" and wrote that it "evokes the nostalgia of better summer days.

[82] On 13 December 2019, Styles performed the song as part of his one night only concert at The Forum in Los Angeles to celebrate the release of Fine Line.

[86] Styles performed the song on 28 February 2020 at the Music Hall of Williamsburg in Brooklyn as part of a secret session with Sirius XM and Pandora.