"Style" is a song by the American singer-songwriter Taylor Swift and the third single from her fifth studio album, 1989 (2014). She wrote the track with its producers Max Martin, Shellback, and Ali Payami. An incorporation of pop, funk, disco, and electronic styles, "Style" is built on an electric guitar riff, pulsing synthesizers, and dense vocal reverb. The lyrics are about a couple who could not escape from an unhealthy relationship because they are never "out of style". Big Machine in partnership with Republic Records released the song to US radio on February 9, 2015.

In the United States, "Style" peaked at number six and was 1989's third consecutive top-ten single on the Billboard Hot 100, and it was certified triple platinum by the Recording Industry Association of America. The single reached number one in South Africa and the top 25 and received multi-platinum certifications in Australia, Canada, New Zealand, and the United Kingdom. Early reviews were generally positive and praised the production but a few of them deemed the lyrics unsophisticated. Retrospective opinions have regarded "Style" as one of Swift's best songs.

Kyle Newman directed the song's music video, which premiered on February 13, 2015. It features Swift and Dominic Sherwood as a couple who reminisce about their relationship through illusions and flashbacks using broken mirror pieces. Swift included "Style" on the set lists for three of her world tours: the 1989 World Tour (2015), the Reputation Stadium Tour (2018), and the Eras Tour (2023–2024). Following a 2019 dispute regarding the ownership of Swift's back catalog, she re-recorded the song as "Style (Taylor's Version)" for her re-recorded album 1989 (Taylor's Version) (2023).

Taylor Swift had identified as a country musician, up until her fourth studio album, Red, which was released on October 22, 2012. Red incorporates eclectic pop and rock styles beyond the country stylings of Swift's past albums, which led to critics questioning her country-music identity. Swift began writing songs for her fifth studio album in mid-2013 while touring on the Red Tour. Inspired by 1980s synth-pop, she named the album 1989 after her birth year to signify an artistic reinvention: she described it as her first "official pop album". In 1989, Swift and the Swedish producer Max Martin served as executive producers. Out of 13 tracks on the standard edition, Martin and his frequent collaborator Shellback produced seven, including "Style".

The producer Ali Payami and the guitarist Niklas Ljungfelt composed the instrumental of "Style", a guitar-driven track inspired by Daft Punk and what Ljungfelt described as "funky electronic music". Payami played the track to Martin, which Swift overheard and led to her becoming fond of the track. She and Martin wrote new lyrics to the instrumental, and Shellback and Payami co-wrote the track. Martin, Shellback, and Payami produced "Style", which was recorded by Michael Illbert and Sam Holland, assisted by Cory Bice, at MXM Studios in Stockholm and Conway Recording Studios in Los Angeles. The song was mixed by Serban Ghenea and John Hanes at MixStar Studios in Virginia Beach, and it was mastered by Tom Coyne at Sterling Sound in New York City. "Style" was the last song produced for 1989; Swift said that once she finished the track, she knew the album was complete: "There was a huge missing piece, and that song filled it."

"Style" features prominent electronic stylings. It incorporates pulsing synthesizers, a throbbing bassline, and dense vocal reverb. The track exhibits eclectic influences: it is built on a recurring electric guitar riff that aligns with funk, R&B, and 1980s rock, and its upbeat groove evokes dance and 1970s disco. The refrain's first half consists of major chords of D and G that create a radiant atmosphere; the second half switches to a B minor chord that creates a rather sorrow one.

Critics mostly categorize "Style" as synth-pop and funk-pop. Other reviews deem it Italo disco and pop rock. Ed Masley in The Arizona Republic and the musicologist James E. Perone regard it as a hybrid of disco and new wave, while Alex Hudson and Megan LaPierre from Exclaim! say that it has a "synthwave atmosphere". According to many critics, "Style" not only resembles the music of the 1980s but also features a modern-leaning production. They liken the sound to the works of 1980s musicians such as Chaka Khan, Nile Rodgers, Don Henley, and Madonna, or contemporary acts such as Daft Punk, Electric Youth, and Blood Orange. Masley writes that the track "would have sounded right at home on MTV a few years earlier than 1989", and Rob Sheffield of Rolling Stone deems it "extremely 1986-sounding". For Perone, although "Style" strongly evokes 1980s music, it does not reference any particular influence.

Swift was inspired to write "Style" by an unstable relationship which she compared to timeless fashion staples. The lyrics are about an on-again, off-again relationship, and the couple in question could not end it because they are never "out of style". The opening lines set a scene, "Midnight/ You come and pick me up, no headlights"; for some critics, these lyrics allude to sex, a theme Swift had not openly embraced—Jon Caramanica of The New York Times cited them as an example of her relinquishing the youthful innocence of her past songs. The refrain depicts the couple as conventionally attractive: the male lover resembles the 1950s actor James Dean with his "daydream look in [his] eye", and the female narrator flaunts her "red lip classic thing that you like" and "good girl faith and a tight little skirt". For some journalists, the beauty depicted is conservative and embedded with racial undertones. In the second pre-chorus, both characters mutually admit to cheating; Swift said the part displayed her evolved viewpoints on past relationships by admitting wrongdoings of both sides instead of her "I was right, you were wrong" mindset in previous songs.