"Blank Space" is a song by the American singer-songwriter Taylor Swift and the second single from her fifth studio album, 1989 (2014). Swift wrote the song with its producers, Max Martin and Shellback. Inspired by the media scrutiny on Swift's love life that affected her girl-next-door reputation, "Blank Space" portrays a flirtatious woman with multiple romantic attachments. It is an electropop track with a minimal arrangement consisting of synthesizers, hip-hop-influenced beats, and layered vocals.

Big Machine in partnership with Republic Records released "Blank Space" to US radio on November 10, 2014. One of the best-selling singles of 2015, it topped charts in Australia, Canada, Iceland, Scotland, and South Africa. In the United States, it spent seven weeks atop the Billboard Hot 100 and was certified eight times platinum by the Recording Industry Association of America (RIAA). Music critics praised the production and Swift's songwriting; some picked it as 1989's highlight. The song earned three nominations at the 58th Grammy Awards, including two general categories: Record of the Year and Song of the Year. Rolling Stone placed it at number 320 on their 2024 revision of the 500 Greatest Songs of All Time.

Joseph Kahn directed the music video for "Blank Space", which depicts Swift as a jealous woman who acts erratically when she suspects her boyfriend's infidelity. The video won Best Pop Video and Best Female Video at the 2015 MTV Video Music Awards, and it ranked 67th on Rolling Stone's 100 Greatest Music Videos of All Time in 2021. Swift included "Blank Space" in the set lists for three of her world tours: the 1989 World Tour (2015), Reputation Stadium Tour (2018), and the Eras Tour (2023–2024). The song was covered by several rock musicians. Following the 2019 dispute regarding the ownership of Swift's back catalog, she re-recorded the song as "Blank Space (Taylor's Version)" for her 2023 re-recorded album 1989 (Taylor's Version).

Inspired by 1980s synth-pop with synthesizers, drum pads, and overlapped vocals, Taylor Swift abandoned the country stylings of her previous releases to incorporate pop production for her fifth studio album, 1989, which was released in 2014. Swift began writing songs for the album in mid-2013 concurrently with the start of Swift's headlining world tour in support of her fourth studio album Red. On 1989, Swift and the Swedish producer Max Martin served as executive producers. Martin and his frequent collaborator Shellback produced seven out of 13 songs on the album's standard edition.

Having been known as "America's Sweetheart" thanks to her wholesome and down-to-earth girl next door image, Swift saw her reputation blemished due to her history of romantic relationships with a series of high-profile celebrities. The New York Times asserted in 2013 that her "dating history [had] begun to stir what feels like the beginning of a backlash", questioning whether Swift was in the midst of a quarter-life crisis. The Tampa Bay Times observed that until the release of 1989, Swift's love life had become a fixed tabloid interest and overshadowed her musicianship. Swift disliked the media portrayal of her as a "serial-dater", feeling that it undermined her professional works, and became reticent to discuss her personal life in public. The tabloid scrutiny on her image prompted her to write satirical songs about her perceived image, in addition to her traditional romantic themes.

Talking to GQ in 2015, Swift said that she envisioned "Blank Space" to be a satirical self-referential nod to the media perception of her image as "a girl who's crazy but seductive but glamorous but nuts but manipulative". She admitted that she had felt personally attacked for a long time before realizing "it was kind of hilarious". She co-wrote the song with its producers, Max Martin and Shellback.

"Blank Space" follows the verse–chorus song structure. The lyrics in the verses are clipped, "Magic, madness, heaven, sin", which the musicologist Nate Sloan said set a mysterious and dreadful tone. At one point, Swift describes herself as a "nightmare dressed like a daydream". The refrain alludes to Swift's songwriting practice taking inspiration from her love life: the lyrics, "Got a long list of ex-lovers They'll tell you I'm insane But I've got a blank space, baby", are followed by a brief silence and then a clicking retractable pen sound, and Swift concludes the refrain: "And I'll write your name." After the song's release, the line "Got a long list of ex-lovers" was misheard by some audience as "All the lonely Starbucks lovers", which prompted internet discussions including a response from Starbucks themselves.

Swift told NME in 2015 that when "Blank Space" was released, "[half] the people got the joke, half the people really think that [she was] really owning the fact that [she was] a psychopath". According to Sloan, the narrator of "Blank Space" is unreliable, and therefore it is open to interpretation whether the song is a true portrayal of Swift's character or not. In contemporary publications, journalists commented that the track represented 1989's lighthearted view on failed relationships and departed from the idealized romance on Swift's past albums. Others wrote that Swift made fun of her image and the media discourse surrounding her celebrity, which later served as the foundation for her sixth studio album Reputation (2017), an album exploring her public experiences and the media gossip.