"Bad Blood" is a song by American singer-songwriter Taylor Swift, taken from her fifth studio album 1989 (2014). Swift wrote the song with its producers Max Martin and Shellback. The album track is a pop song with stomping drums.
A hip hop remix of "Bad Blood" featuring American rapper Kendrick Lamar was released as the fourth single from 1989 on May 17, 2015, by Big Machine and Republic Records.
The song is about feelings of betrayal by a close friend. Upon the album's release, critics expressed mixed opinions about "Bad Blood", with some complimenting Swift's defiant attitude and dubbing it an album highlight, while others criticized its production and lyrics. The remixed single was praised for the reworked instrumentation and Lamar's verses, which some considered out of place on a pop song. Media outlets speculated that American singer Katy Perry is the subject of the song.
"Bad Blood" was supported by a high-budget music video directed by Joseph Kahn and produced by Swift. It featured an ensemble cast consisting of many singers, actresses and fashion models, which received wide media coverage. Critics praised the video for its cinematic and futuristic visuals inspired by neo-noir styles.
It won a Grammy Award for Best Music Video, and two MTV Video Music Awards for the Video of the Year and Best Collaboration. Commercially, "Bad Blood" was a chart success, reaching number one in Australia, Canada, New Zealand, Scotland, as well as the United States where it peaked atop the Billboard Hot 100, Adult Top 40 and Mainstream Top 40. It further charted inside the top 10 in Hungary, Ireland, Lebanon, South Africa, and the United Kingdom.
It has been certified triple platinum in Australia and Canada, and 6× platinum in the US. The song received a Grammy nomination for Best Pop Duo/Group Performance.