"Look What You Made Me Do" is a song recorded by American singer-songwriter Taylor Swift. It was released on August 24, 2017, by Big Machine Records, as the lead single from her sixth studio album, Reputation (2017).
Swift wrote and produced the song with Jack Antonoff. Released after a year of her public hiatus, several publications have noted the song as one of pop music's most memorable comebacks, buoyed by its accompanying music video.
The single is a dance-pop, electropop, and progressive pop song with lyrics about various events that contributed to the tarnish of Swift's repute. Right Said Fred members (Richard Fairbrass, Fred Fairbrass, and Rob Manzoli) received songwriting credits since the hook "Look What You Made Me Do" interpolates the melody of their 1991 song "I'm Too Sexy".
Upon release, the song polarized music critics, some of whom complimented Swift's new direction and praised it as a fierce return, while others were disappointed with her change of style.
Breaking a string of records, "Look What You Made Me Do" became Swift's fifth number-one single on the US Billboard Hot 100 and one of the most dominant number-one hits in the chart's history. It amassed the most plays in a single day on Spotify and topped the Hot 100 for three consecutive weeks.
It also debuted atop the Billboard Digital Song Sales and Streaming Songs charts, with 353,000 song downloads and 84.4 million streams. The song debuted and peaked at number-one in several countries worldwide, including Australia, Canada, Ireland, Japan, Malaysia, New Zealand, the Philippines, Scotland and the UK.
The music video, directed by Joseph Kahn, premiered at the 2017 MTV Video Music Awards, three days after the song's release. Upon its release on YouTube, the music video garnered 43.2 million views in its first 24 hours, breaking the record for the most views in its first 24 hours of release, at that time; it also broke the 24-hour Vevo record, which is now held by Swift's own 2019 single "Me!".
The video garnered critical acclaim, and was ranked by Billboard and Rolling Stone as one of the best music videos of 2017. As of July 2018, "Look What You Made Me Do" is certified 4× Platinum by the Recording Industry Association of America for exceeding 4 million units in the US. The song has also received platinum or multi-platinum certifications in Australia, Belgium, Canada, Denmark, Italy, New Zealand, Norway, Poland, Portugal, Sweden, and the United Kingdom, and a diamond certification in Brazil.